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  • 1551. Tsuboi, Masahito
    et al.
    Gonzalez-Voyer, Alejandro
    Kolm, Niclas
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Phenotypic integration of brain size and head morphology in Lake Tanganyika Cichlids2014Inngår i: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 14, s. 39-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Phenotypic integration among different anatomical parts of the head is a common phenomenon across vertebrates. Interestingly, despite centuries of research into the factors that contribute to the existing variation in brain size among vertebrates, little is known about the role of phenotypic integration in brain size diversification. Here we used geometric morphometrics on the morphologically diverse Tanganyikan cichlids to investigate phenotypic integration across key morphological aspects of the head. Then, while taking the effect of shared ancestry into account, we tested if head shape was associated with brain size while controlling for the potentially confounding effect of feeding strategy. Results: The shapes of the anterior and posterior parts of the head were strongly correlated, indicating that the head represents an integrated morphological unit in Lake Tanganyika cichlids. After controlling for phylogenetic non-independence, we also found evolutionary associations between head shape, brain size and feeding ecology. Conclusions: Geometric morphometrics and phylogenetic comparative analyses revealed that the anterior and posterior parts of the head are integrated, and that head morphology is associated with brain size and feeding ecology in Tanganyikan cichlid fishes. In light of previous results on mammals, our results suggest that the influence of phenotypic integration on brain diversification is a general process.

  • 1552. Tsuboi, Masahito
    et al.
    Kotrschal, Alexander
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Hayward, Alexander
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Buechel, Severine Denise
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Zidar, Josefina
    Lovlie, Hanne
    Kolm, Niclas
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Evolution of brain-body allometry in Lake Tanganyika cichlids2016Inngår i: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 70, nr 7, s. 1559-1568Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Brain size is strongly associated with body size in all vertebrates. This relationship has been hypothesized to be an important constraint on adaptive brain size evolution. The essential assumption behind this idea is that static (i.e., within species) brain-body allometry has low ability to evolve. However, recent studies have reported mixed support for this view. Here, we examine brain-body static allometry in Lake Tanganyika cichlids using a phylogenetic comparative framework. We found considerable variation in the static allometric intercept, which explained the majority of variation in absolute and relative brain size. In contrast, the slope of the brain-body static allometry had relatively low variation, which explained less variation in absolute and relative brain size compared to the intercept and body size. Further examination of the tempo and mode of evolution of static allometric parameters confirmed these observations. Moreover, the estimated evolutionary parameters indicate that the limited observed variation in the static allometric slope could be a result of strong stabilizing selection. Overall, our findings suggest that the brain-body static allometric slope may represent an evolutionary constraint in Lake Tanganyika cichlids.

  • 1553.
    Tsuboi, Masahito
    et al.
    Evolutionary Biology Centre, Department of Ecology and Genetics/Animal Ecology, Uppsala University, Uppsala, Sweden.
    Kotrschal, Alexander
    Department of Zoology/Ethology, Stockholm University, Stockholm, Sweden.
    Hayward, Alexander
    Department of Zoology/Ethology, Stockholm University, Stockholm, Sweden.
    Buechel, Severine Denise
    Department of Zoology/Ethology, Stockholm University, Stockholm, Sweden.
    Zidar, Josefina
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Lovlie, Hanne
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    Kolm, Niclas
    Department of Zoology/Ethology, Stockholm University, Stockholm, Sweden.
    Evolution of brain-body allometry in Lake Tanganyika cichlids.2016Inngår i: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 70, nr 7, s. 1559-1568Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Brain size is strongly associated with body size in all vertebrates. This relationship has been hypothesized to be an important constraint on adaptive brain size evolution. The essential assumption behind this idea is that static (i.e., within species) brain-body allometry has low ability to evolve. However, recent studies have reported mixed support for this view. Here, we examine brain-body static allometry in Lake Tanganyika cichlids using a phylogenetic comparative framework. We found considerable variation in the static allometric intercept, which explained the majority of variation in absolute and relative brain size. In contrast, the slope of the brain-body static allometry had relatively low variation, which explained less variation in absolute and relative brain size compared to the intercept and body size. Further examination of the tempo and mode of evolution of static allometric parameters confirmed these observations. Moreover, the estimated evolutionary parameters indicate that the limited observed variation in the static allometric slope could be a result of strong stabilizing selection. Overall, our findings suggest that the brain-body static allometric slope may represent an evolutionary constraint in Lake Tanganyika cichlids.

  • 1554.
    Tsuboi, Masahito
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Kotrschal, Alexander
    Stockholm Univ, Dept Zool Ethol, Svante Arrhenius Vag 18B, SE-10691 Stockholm, Sweden.
    Hayward, Alexander
    Stockholm Univ, Dept Zool Ethol, Svante Arrhenius Vag 18B, SE-10691 Stockholm, Sweden.
    Buechel, Séverine
    Stockholm Univ, Dept Zool Ethol, Svante Arrhenius Vag 18B, SE-10691 Stockholm, Sweden.
    Zidar, Josefina
    Linkoping Univ, IFM Biol, Campus Valla, SE-58183 Linkoping, Sweden.
    Løvlie, Hanne
    Linkoping Univ, IFM Biol, Campus Valla, SE-58183 Linkoping, Sweden.
    Kolm, Niclas
    Stockholm Univ, Dept Zool Ethol, Svante Arrhenius Vag 18B, SE-10691 Stockholm, Sweden.
    Evolution of brain-body allometry in Lake Tanganyika cichlids2016Inngår i: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 70, nr 7, s. 1559-1568Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Brain size is strongly associated with body size at all taxonomic levels. This relationship has been hypothesized to be an important constraint on adaptive brain size evolution. The essential assumption of this idea is that allometry has a limited ability to evolve, and that evolution of relative brain size is therefore constrained to occur along the direction of static (i.e. within species) allometry. However, recent studies have reported mixed support for this view. Here, we examine if static allometry has affected the rate of relative brain size evolution in Lake Tanganyika cichlids. The evolution of brain-body allometry showed a recent rapid divergence whereas brain size evolution represented a more gradual phenotypic divergence across the history of diversification. Accordingly, we found no support for that static allometry affected the rate of absolute or relative brain size evolution in this group. Instead, we detected low, but existing evolvability of static allometry. Moreover, static allometry evolved faster in species with relatively small and large brains than in species with medium brain size. We propose that a combination of allometric constraints and partial evolvability of static allometry have allowed for independent evolution of brain size in Lake Tanganyika cichlids. Overall, our results demonstrate a complex, yet important, role of brain-body allometry in brain size evolution. 

  • 1555.
    Tsuboi, Masahito
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Lim, A. C. O.
    Univ Malaya, Inst Biol Sci, Fac Sci, Kuala Lumpur, Malaysia.; Save Our Seahorses Malaysia, Petaling Jaya, Selangor, Malaysia..
    Ooi, B. L.
    Univ Malaya, Inst Biol Sci, Fac Sci, Kuala Lumpur, Malaysia.; Save Our Seahorses Malaysia, Petaling Jaya, Selangor, Malaysia..
    Yip, M. Y.
    Univ Malaya, Inst Biol Sci, Fac Sci, Kuala Lumpur, Malaysia.; Save Our Seahorses Malaysia, Petaling Jaya, Selangor, Malaysia..
    Chong, V. C.
    Univ Malaya, Inst Biol Sci, Fac Sci, Kuala Lumpur, Malaysia.; Univ Malaya, Inst Ocean & Earth Sci, Kuala Lumpur, Malaysia..
    Ahnesjö, Ingrid
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Kolm, N.
    Stockholm Univ, Dept Zool Ethol, Stockholm, Sweden..
    Brain size evolution in pipefishes and seahorses: the role of feeding ecology, life history and sexual selection2017Inngår i: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 30, nr 1, s. 150-160Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Brain size varies greatly at all taxonomic levels. Feeding ecology, life history and sexual selection have been proposed as key components in generating contemporary diversity in brain size across vertebrates. Analyses of brain size evolution have, however, been limited to lineages where males predominantly compete for mating and females choose mates. Here, we present the first original data set of brain sizes in pipefishes and seahorses (Syngnathidae) a group in which intense female mating competition occurs in many species. After controlling for the effect of shared ancestry and overall body size, brain size was positively correlated with relative snout length. Moreover, we found that females, on average, had 4.3% heavier brains than males and that polyandrous species demonstrated more pronounced (11.7%) female-biased brain size dimorphism. Our results suggest that adaptations for feeding on mobile prey items and sexual selection in females are important factors in brain size evolution of pipefishes and seahorses. Most importantly, our study supports the idea that sexual selection plays a major role in brain size evolution, regardless of on which sex sexual selection acts stronger.

  • 1556.
    Tsuboi, Masahito
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Lim, Adam Chee Ooi
    Ooi, Boon Leong
    Mei, Yee Yip
    Chong, Ving Ching
    Ahnesjö, Ingrid
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Kolm, Niclas
    Prey motility, egg size and female mating competition: brain size evolution in pipefishes and seahorsesManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Brain size varies greatly at all taxonomic levels. Feeding ecology, life history and sexual selection have been proposed as key components in generating the existing contemporary diversity in brain size across vertebrates. Analyses of brain size evolution have, however, been limited to lineages where males predominantly compete for mating and females choose mates. Here, we present the first original data set of brain sizes in pipefishes and seahorses (Syngnathidae). In this group, intense female mating competition occurs in many species (i.e. reversed sex-roles), and mating patterns include monogamy, polygynandry and polyandry. After controlling for the effect of shared ancestry and overall body size, relatively larger brains were positively correlated with relatively longer snout length, which is related to the propensity for feeding on motile and evasive prey items in Syngnathidae, and larger egg size. Furthermore, we found that females, on average, had 4.3% heavier brains than males and that polyandrous species tended to demonstrate female-favored brain size dimorphism. Our results suggest that adaptations for feeding on motile prey items, energetic constraints associated with production of large-brained juveniles and sexual selection in females are important factors in brain size evolution of pipefishes and seahorses.

  • 1557.
    Tsuboi, Masahito
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Shoji, Jun
    Sogabe, Atsushi
    Ahnesjö, Ingrid
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Kolm, Niclas
    Within species support for the expensive tissue hypothesis: a negative association between brain size and visceral fat storage in females of Pacific seaweed pipefishManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    The brain is one of the most energetically expensive organs in the vertebrate body. Consequently, the high cost of brain development and maintenance is predicted to constrain adaptive brain size evolution (the expensive tissue hypothesis, ETH). Here, we test the ETH in a teleost fish with predominant female mating competition (reversed sex-roles) and male pregnancy, the pacific seaweed pipefish Syngnathus schlegeli. The relative size of the brain and other energetically expensive organs (kidney, liver, heart, gut, visceral fat, ovary/testis) was compared among three groups: pregnant males, non-pregnant males and egg producing females. Brood size in pregnant males was unrelated to brain size or the size of any other organ, whereas positive relationships were found between ovary size, kidney size and liver size in females. Moreover, we found that the size a suite of energetically expensive organs (brain, heart, gut, kidney, liver) as well as the amount of visceral fat did not differ between pregnant and non-pregnant males. However, we found marked differences in relative size of the expensive organs between sexes. Females had larger liver and kidney than males, whereas males stored more visceral fat than females. Furthermore, in females we found a negative correlation between brain size and the amount of visceral fat, whereas in males a positive trend between brain size and both liver and heart size was found. These results suggest that, while the majority of variation in the size of various expensive organs in this species likely reflects that individuals in good condition can afford to allocate resources to several organs, the cost of the expensive brain was visible in the visceral fat content of females, possibly due to the high costs associated with female egg production. 

  • 1558.
    Tsuda, Yoshiaki
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution. CNR, Inst Biosci & Bioresources, Via Madonna del Piano 10, I-50019 Florence, Italy..
    Chen, Jun
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Stocks, Michael
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Källman, Thomas
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk biokemi och mikrobiologi.
    Sonstebo, Jorn Henrik
    Norwegian Inst Bioecon Res, Post Box 115, N-1431 As, Norway..
    Parducci, Laura
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Semerikov, Vladimir
    Russian Acad Sci, Inst Plant & Anim Ecol, Urals Div, 8 Marta Str,202, Ekaterinburg 620144, Russia..
    Sperisen, Christoph
    Swiss Fed Res Inst Forest, Snow & Landscape Res WSL, Zurcherstr 111, CH-8903 Birmensdorf, Switzerland..
    Politov, Dmitry
    Russian Acad Sci, Vavilov Inst Gen Genet, Gubkin Str 3, Moscow 119991, Russia..
    Ronkainen, Tiina
    Univ Helsinki, Dept Environm Sci, Environm Change Res Unit, POB 65, FI-00014 Helsinki, Finland..
    Valiranta, Minna
    Univ Helsinki, Dept Environm Sci, Environm Change Res Unit, POB 65, FI-00014 Helsinki, Finland..
    Vendramin, Giovanni Giuseppe
    CNR, Inst Biosci & Bioresources, Via Madonna del Piano 10, I-50019 Florence, Italy..
    Tollefsrud, Mari Mette
    Norwegian Inst Bioecon Res, Post Box 115, N-1431 As, Norway..
    Lascoux, Martin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    The extent and meaning of hybridization and introgression between Siberian spruce (Picea obovata) and Norway spruce (Picea abies): cryptic refugia as stepping stones to the west?2016Inngår i: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 25, nr 12, s. 2773-2789Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Boreal species were repeatedly exposed to ice ages and went through cycles of contraction and expansion while sister species alternated periods of contact and isolation. The resulting genetic structure is consequently complex, and demographic inferences are intrinsically challenging. The range of Norway spruce (Picea abies) and Siberian spruce (Picea obovata) covers most of northern Eurasia; yet their geographical limits and histories remain poorly understood. To delineate the hybrid zone between the two species and reconstruct their joint demographic history, we analysed variation at nuclear SSR and mitochondrial DNA in 102 and 88 populations, respectively. The dynamics of the hybrid zone was analysed with approximate Bayesian computation (ABC) followed by posterior predictive STRUCTURE plot reconstruction and the presence of barriers across the range tested with estimated effective migration surfaces. To estimate the divergence time between the two species, nuclear sequences from two well-separated populations of each species were analysed with ABC. Two main barriers divide the range of the two species: one corresponds to the hybrid zone between them, and the other separates the southern and northern domains of Norway spruce. The hybrid zone is centred on the Urals, but the genetic impact of Siberian spruce extends further west. The joint distribution of mitochondrial and nuclear variation indicates an introgression of mitochondrial DNA from Norway spruce into Siberian spruce. Overall, our data reveal a demographic history where the two species interacted frequently and where migrants originating from the Urals and the West Siberian Plain recolonized northern Russia and Scandinavia using scattered refugial populations of Norway spruce as stepping stones towards the west.

  • 1559.
    Tsuda, Yoshiaki
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution. Uppsala universitet, Science for Life Laboratory, SciLifeLab. CNR, Div Florence, Inst Biosci & Bioresources, Via Madonna del Piano 10, I-50019 Florence, Italy..
    Semerikov, Vladimir
    Russian Acad Sci, Ural Branch, Inst Plant & Anim Ecol, Ekaterinburg 620144, Russia..
    Sebastiani, Federico
    CNR, Div Florence, Inst Biosci & Bioresources, Via Madonna del Piano 10, I-50019 Florence, Italy..
    Vendramin, Giovanni Giuseppe
    CNR, Div Florence, Inst Biosci & Bioresources, Via Madonna del Piano 10, I-50019 Florence, Italy..
    Lascoux, Martin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution. Uppsala universitet, Science for Life Laboratory, SciLifeLab. Uppsala Univ, Sci Life Lab, Evolutionary Biol Ctr, Dept Ecol & Genet, Norbyvagen 18D, S-75236 Uppsala, Sweden..
    Multispecies genetic structure and hybridization in the Betula genus across Eurasia2017Inngår i: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 26, nr 2, s. 589-605Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Boreal and cool temperate forests are the major land cover of northern Eurasia, and information about continental-scale genetic structure and past demographic history of forest species is important from an evolutionary perspective and has conservation implications. However, although many population genetic studies of forest tree species have been conducted in Europe or Eastern Asia, continental-scale genetic structure and past demographic history remain poorly known. Here, we focus on the birch genus Betula, which is commonly distributed in boreal and cool temperate forests, and examine 129 populations of two tetraploid and four diploid species collected from Iceland to Japan. All individuals were genotyped at seven to 18 nuclear simple sequence repeats (nSSRs). Pairwise <mml:msubsup>FST</mml:msubsup> among the six species ranged from 0.285 to 0.903, and genetic differentiation among them was clear. structure analysis suggested that Betula pubescens is an allotetraploid and one of the parental species was Betula pendula. In both species pairs of B.pendula and B.plathyphylla, and B.pubescens and B.ermanii, genetic diversity was highest in central Siberia. A hybrid zone was detected around Lake Baikal for eastern and western species pairs regardless of ploidy level. Approximate Bayesian computation suggested that the divergence of B.pendula and B.platyphylla occurred around the beginning of the last ice age (36300years BP, 95% CI: 15330-92700) and hybridization between them was inferred to have occurred after the last glacial maximum (1614years BP, 95% CI: 561-4710), with B.pendula providing a higher contribution to hybrids.

  • 1560.
    Tsutsumi, Chie
    et al.
    Natl Museum Nat & Sci, Dept Bot, Amakubo 4-1-1, Tsukuba, Ibaraki 3050005, Japan..
    Chen, Cheng-Wei
    Taiwan Forestry Res Inst, Bot Garden Div, Taipei 100, Taiwan..
    Larsson, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Systematisk biologi.
    Hirayama, Yumiko
    Natl Museum Nat & Sci, Dept Bot, Amakubo 4-1-1, Tsukuba, Ibaraki 3050005, Japan..
    Kato, Masahiro
    Natl Museum Nat & Sci, Dept Bot, Amakubo 4-1-1, Tsukuba, Ibaraki 3050005, Japan..
    Phylogeny and classification of Davalliaceae on the basis of chloroplast and nuclear markers2016Inngår i: Taxon, ISSN 0040-0262, E-ISSN 1996-8175, Vol. 65, nr 6, s. 1236-1248Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Davalliaceae have been classified on the basis of morphological data or morphological and molecular data. The family has been divided into various genera, the circumscription of which may differ between authors. Previous phylogenetic analyses used limited numbers of genes and taxa. We studied the molecular phylogeny of the family by using two nuclear markers (LEAFY intron 1, gapCp intron) and a long chloroplast marker (atpB-rbcL-accD) in 55 specimens of 41 species. The results indicated that Davalliaceae are divided into seven clades, six of which coincide with the genera and sections sensu Kato & Tsutsumi. The relationships among the clades were inconsistent with respect to the markers analyzed, and a species tree derived from all datasets did not resolve the relationships. In addition, the clades were not well characterized to be classified at the genus level. Therefore, we propose to classify Davalliaceae in the single genus Davallia with seven sections, i.e., sect. Araiostegiella, sect. Davallia (comprising only D. canariensis), sect. Davallodes (including Araiostegia p.p. and Paradavallodes), sect. Humata (including Pachypleuria and Parasorus), sect. Scyphularia (s.l. = sect. Davallia sensu Kato & Tsutsumi excluding the type), sect. Trogostolon (s.l. = sect. Trogostolon sensu Kato & Tsutsumi), and sect. Cordisquama (s.l. = Wibelia sensu Kato & Tsutsumi). A key to the sections and a table of characters for the sections are provided.

  • 1561.
    Tullberg, Birgitta S.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Tullberg, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    A model of actions and norms: An integrated evolutionary perspective on normative ethics and human behavior2011Inngår i: Biology and Politics: The Cutting Edge / [ed] Peterson, S. A.; Somit, A., Emerald Group Publishing Limited, 2011, s. 29-51Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    One fundamental question in normative ethics concerns how norms influence human behavior and discussions within normative ethics would be facilitated by a classification that treats human actions/behavior and moral norms within the same functional framework. Based on evolutionary analysis of benefits and costs, we distinguish five categories of human action. Four of these – self-interest, kin selection, group egoism, and cooperation – are basically results of gene selection, benefit the individual's genetic interest and may be described as “broad self-interest.” In contrast, the fifth category, unselfishness, is more likely a result of cultural influences. All the five categories of action are influenced by three broad moral spheres, each of which represents many norms that have a common denominator. Thus, a sphere of integrity concerns the individual's right to act in his/her interest and against those of other individuals. A sphere of reciprocal morality deals with rules for various forms of cooperation. An altruistic sphere has to do with the obligations to generate advantages for others. Ethics can be viewed as a dynamic conflict among various norms within and between these spheres. The classical conflict is that between the integrity and altruistic spheres. However, we argue that the prime antagonism may be that between the altruistic and reciprocal spheres; the main impact of altruistic ideals may not be the reputed one of counteracting egoism, but subversively thwarting reciprocal morality.

  • 1562.
    Täljedal, Inge-Bert
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB).
    Linnaeus's Questions to the Sami Herdsman: The ID-versus-Science Issue in a Nutshell2010Inngår i: Philosophy of the social sciences, ISSN 0048-3931, E-ISSN 1552-7441, Vol. 40, nr 3, s. 456-466Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    According to a U.S. court ruling, intelligent design (ID) theory is religious in nature, not scientific, and must not be taught in schools. In opposition, Fuller argues for a closer rapport between science and religion. Here it is emphasized that any allegedly scientific conclusion from design in nature to the existence of God is a hypothesis subject to the same quality norms as empirical hypotheses in general. By quotations from his Iter Lapponicum, Linnaeus is summoned in support of a strictly immanent conception of science, against Fuller's suggestion that Linnaeus' personal piety could be a reason for considering ID scientific.

  • 1563.
    Uebbing, Severin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    On the Evolution of the Avian Transcriptome2015Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Change in gene expression is a powerful tool for evolution, because seemingly small expression changes can contribute important steps towards adaptation without necessarily affecting the whole organism. There is still much to learn about how gene expression evolves on genome- and population-wide levels, especially in non-model organisms. This thesis addresses some important questions in gene expression evolution via the quantitative measurement of RNA and protein levels in birds.

    First, I confirmed the state of incomplete dosage compensation in birds by sequencing the transcriptome of collared flycatchers (Ficedula albicollis). I showed that pleiotropy governs the evolution of expression male-bias from the Z chromosome. Sex-linked genes in females were more highly expressed than half the male expression level, indicative of a partial up-regulation. A comparison with data from ostrich (Struthio camelus), a bird with non-degenerated sex chromosomes, showed that sex-linked expression male-bias evolved following sex chromosome degradation.

    Second, using a combination of RNA sequencing and proteome mass spectrometry in chicken (Gallus gallus), I asked whether complete dosage compensation was achieved through regulation at translation. I showed that this was not the case and that incomplete dosage compensation extends to the protein level in birds. In addition, sex-linked genes showed more often an increased amount of regulation at translational level than autosomal genes.

    Third, I investigated gene expression divergence between collared and pied flycatchers (Ficedula hypoleuca) using RNA sequencing in multiple tissues and individuals. Tissues differed in the degree of expression variance and in the number of divergent genes, which I identified using expression QST. Variance within species was negatively correlated with expression breadth and protein interactivity, indicating that evolutionary constraints act predominantly within interbreeding populations. Among genes unique to one of the species, I identified one gene, DPP7, falling into a large genomic deletion fixed in pied flycatchers.

    Fourth, I investigated allele-specific expression (ASE) in the two flycatcher populations. ASE was identified from genetic variants within transcripts using RNA sequencing reads. We developed a Bayesian negative binomial approach that gained statistical power by estimating expression variance from combined SNPs within a transcript and overdispersion from the whole dataset.

  • 1564.
    Uebbing, Severin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Backström, Niclas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Bolivar, Paulina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Burri, Reto
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Ludovic, Dutoit
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Mugal, Carina F.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Nater, Alexander
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Ellegren, Hans
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Divergence in gene expression within and between two closely related flycatcher speciesManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Compared to DNA sequence evolution, relatively little is known about the character of gene expression evolution as species diverge. For example, it is unclear if gene expression generally evolves in a clock-like manner (by stabilizing selection or from neutral evolution) or if there are frequent episodes of directional selection. To gain insights into the evolutionary divergence of gene expression patterns, we sequenced and compared the transcriptomes of multiple tissues from population samples of collared (Ficedula albicollis) and pied flycatchers (F. hypoleuca), a species pair which diverged less than one million years ago. Tissues resolved into separate clusters in non-metric multidimensional scaling ordination analysis and samples from the two species generally clustered by tissue rather than by species. Tissues differed in the degrees of expression variance within species and divergence between species. Variance was positively correlated with expression breadth and negatively correlated with protein interactivity, suggesting that pleiotropic constraints reduce gene expression variance within species. Variance was correlated with between-species divergence, consistent with a pattern expected from stabilizing selection and neutral evolution. Using an expression QST approach, we identified genes differentially expressed between species. We also identified 10 genes uniquely expressed in one of the species. For one such gene (DPP7, uniquely expressed in collared flycatcher), the absence of expression in pied flycatchers could be associated with a fixed ≈ 20 kb deletion including 11 out of 13 exons in this species. This study conducted in a young vertebrate speciation model system expands our knowledge of how gene expression evolves in natural populations.

  • 1565.
    Uebbing, Severin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Konzer, Anne
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Xu, Luohao
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Backström, Niclas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Brunström, Björn
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Miljötoxikologi.
    Bergquist, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Ellegren, Hans
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Quantitative Mass Spectrometry Reveals Partial Translational Regulation for Dosage Compensation in Chicken2015Inngår i: Molecular biology and evolution, ISSN 0737-4038, E-ISSN 1537-1719, Vol. 32, nr 10, s. 2716-2725Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    There is increasing evidence that dosage compensation is not a ubiquitous feature following sex chromosome evolution, especially not in organisms where females are the heterogametic sex, like in birds. Even when it occurs, compensation can be incomplete and limited to dosage-sensitive genes. However, previous work has mainly studied transcriptional regulation of sex-linked genes, which may not reflect expression at the protein level. Here, we used liquid chromatography–tandem mass spectrometry to detect and quantify expressed levels of more than 2,400 proteins in ten different tissues of male and female chicken embryos. For comparison, transcriptome sequencing was performed in the same individuals, five of each sex. The proteomic analysis revealed that dosage compensation was incomplete, with a mean male-to-female (M:F) expression ratio of Z-linked genes of 1.32 across tissues, similar to that at the RNA level (1.29). The mean Z chromosome-to-autosome expression ratio was close to 1 in males and lower than 1 in females, consistent with partly reduced Z chromosome expression in females. Although our results exclude a general mechanism for chromosome-wide dosage compensation at translation, 30% of all proteins encoded from Z-linked genes showed a significant change in the M:F ratio compared with the corresponding ratio at the RNA level. This resulted in a pattern where some genes showed balanced expression between sexes and some close to 2-fold higher expression in males. This suggests that proteomic analyses will be necessary to reveal a more complete picture of gene regulation and sex chromosome evolution.

  • 1566.
    Uebbing, Severin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik.
    Künstner, Axel
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik.
    Mäkinen, Hannu
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik.
    Backström, Niclas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Bolivar, Paulina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Burri, Reto
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Dutoit, Ludovic
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Mugal, Carina F.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Nater, Alexander
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Aken, Bronwen
    Flicek, Paul
    Martin, Fergal J
    Searle, Stephen M J
    Ellegren, Hans
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Divergence in gene expression within and between two closely related flycatcher species2016Inngår i: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 25, nr 9, s. 2015-2028Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Relatively little is known about the character of gene expression evolution as species diverge. It is for instance unclear if gene expression generally evolves in a clock-like manner (by stabilizing selection or neutral evolution) or if there are frequent episodes of directional selection. To gain insights into the evolutionary divergence of gene expression, we sequenced and compared the transcriptomes of multiple organs from population samples of collared (Ficedula albicollis) and pied flycatchers (F. hypoleuca), two species which diverged less than one million years ago. Ordination analysis separated samples by organ rather than by species. Organs differed in their degrees of expression variance within species and expression divergence between species. Variance was negatively correlated with expression breadth and protein interactivity, suggesting that pleiotropic constraints reduce gene expression variance within species. Variance was correlated with between-species divergence, consistent with a pattern expected from stabilizing selection and neutral evolution. Using an expression PST approach, we identified genes differentially expressed between species and found 16 genes uniquely expressed in one of the species. For one of these, DPP7, uniquely expressed in collared flycatcher, the absence of expression in pied flycatcher could be associated with a ≈ 20 kb deletion including 11 out of 13 exons. This study of a young vertebrate speciation model system expands our knowledge of how gene expression evolves as natural populations become reproductively isolated.

  • 1567.
    Undin, Malin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för biologisk grundutbildning.
    Spatial variation in the pollinator community in a nursey pollination system with tremendous floral display variation2017Independent thesis Advanced level (degree of Master (Two Years)), 30 poäng / 45 hpOppgave
    Abstract [en]

    Interactions between species are strong drivers of both diversification and maintenance of biodiversity. According to the geographic mosaic theory of coevolution, an interaction between the same species pair can have different outcomes when occurring in different environments. Several recent studies indicate that a key factor affecting the coevolutionary outcome is the local species community composition. For example, the interaction between Woodland Star plants (Lithophragma spp., Saxifragaceae) and the highly specialized nursery pollinator Greya politella (Prodoxidae) can be affected by the local presence of other Greya species. In some populations of the species L. parviflorum, high abundance of co-pollinators also affects the interaction, because the plants in these populations are no longer depending on the nursey pollinator for reproduction. In the remaining Greya-pollinated Lithophragma species, however, the plant-moth interaction has traditionally been considered a close to obligate mutualism. Therefore, it is interesting that recent data report tremendous among- and within-species variation in several floral traits important for Greya moth attraction. This contrasts with predictions from coevolutionary theory, which suggest that selection should act stabilizing on traits important for tight mutualisms in stable environments. Here, I investigate whether spatial variation in the presence of co-pollinators could help explain this variation, focusing on the species L. bolanderi. To do this, I utilize that G. politella oviposition leave readily detectable traces in the Lithophragma capsules. This unique feature provides the possibility to score the contribution of G. politella oviposition to pollination post-flowering. In total, I collected developing capsules from nine L. bolanderi populations distributed across its Sierra Nevadan range to investigate the importance of G. politella versus co-pollinators for seed set. In addition, using two of these populations, I first conducted laboratory pollination efficacy experiments to determine the Greya moth contribution to pollination during nectaring. Second, I conducted repeated flower visitor observations to assess among-population variation in visitation rate by Greya moths and more generalized pollinators. Together, my results show (i) that the importance of G. politella pollination varies dramatically among L. bolanderi populations, (ii) that nectaring Greya moths are probably only weakly contributing to pollination, and (iii) that the contribution to pollination by generalist co-pollinators, such as solitary bees, is spatially variable and may outweigh the pollination by G. politella in some populations. This suggests that the large among-population variation in the floral display traits of L. bolanderi could be generated in a selection mosaic of populations relying to different extents on pollination by G. politella and more generalized co-pollinators. 

  • 1568.
    van der Bijl, Wouter
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Why and how brain size evolves: Sociality, predation and allometry2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The evolution of the vertebrate brain has remained a topic of intense interest from biologists over many decades. Evolutionary biologists have seen it as an intriguing example of how the size and structure of a trait evolves across large phylogenies and under body size constraints, with both large shifts in deep evolutionary time and continuous smaller scale adaptation. Behavioral ecologists, on the other hand, have put great effort in trying to understand the costs and benefits of brain size and structural variation, usually assuming that the brain morphology of species is the result of a balance between energetic costs and cognitive benefits.

    I discuss two hypotheses that aim to explain under what circumstances a higher cognitive ability yields fitness benefits. The predation avoidance hypothesis states that large brains help to avoid predators. The social brain hypothesis predicts that cognition is especially beneficial for animals living in complex social environments. In practice these hypotheses are difficult to differentiate (paper I), as sociality often evolves in response to predation pressure. Comparative studies on either hypothesis should therefore aim to control for effects of the other hypothesis, and experiments may be especially useful in testing more explicit mechanistic explanations.

    I put the predation hypothesis to the test using two approaches, a comparative analysis and a within-species experiment. The comparative analysis (paper II) used published data on hawk predation and related it to both relative brain size and relative telencephalon size. While sparrowhawk predation was unrelated to brain morphology, birds that experience more goshawk predation had larger brains and telencephali. Next, I performed an experiment (paper III) on guppies that had been artificially selected for relative brain size. The selection lines have demonstrated differences in cognitive ability, as well as a marked survival difference under predation in females. I exposed fish to either a predator model or a novel object control, varying both sex and group size. Large-brained females performed fewer and shorter predator inspections than small-brained females, while keeping a larger distance from the predator model.

    I performed another experiment (paper IV) to investigate differences in social competence. I calculated the duration of contests between random pairs of small- and large-brained males, using movement data. When the loser was large-brained, contests were decided almost 40 minutes earlier than when the loser was small-brained, indicating that the decision for the loser to give up is made quicker with a larger brain.

    This thesis ends with an exploration of variation in the scaling relationship between brain and body size across vertebrates (paper V). The observed scaling between brain and body depends on what taxonomic level is under investigation. This effect, however, exclusively occurs in the two classes with the largest brains, mammals and birds. This indicates that strong developmental constraints have been alleviated in the two highly encephalized classes, but not elsewhere.

    In conclusion, I find evidence that both predator avoidance and social factors may contribute to the evolution of brain size. Further work on explicit behavioral frameworks for cognitive benefit hypotheses is likely to yield significant insight. Constraints in brain size may be hard to overcome and play an especially large role at a larger taxonomic scale.

  • 1569.
    van der Bijl, Wouter
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Kolm, Niclas
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Why direct effects of predation complicate the social brain hypothesis And how incorporation of explicit proximate behavioral mechanisms might help2016Inngår i: Bioessays, ISSN 0265-9247, E-ISSN 1521-1878, Vol. 38, nr 6, s. 568-577Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A growing number of studies have found that large brains may help animals survive by avoiding predation. These studies provide an alternative explanation for existing correlative evidence for one of the dominant hypotheses regarding the evolution of brain size in animals, the social brain hypothesis (SBH). The SBH proposes that social complexity is a major evolutionary driver of large brains. However, if predation both directly selects for large brains and higher levels of sociality, correlations between sociality and brain size may be spurious. We argue that tests of the SBH should take direct effects of predation into account, either by explicitly including them in comparative analyses or by pin-pointing the brain-behavior-fitness pathway through which the SBH operates. Existing data and theory on social behavior can then be used to identify precise candidate mechanisms and formulate new testable predictions.

  • 1570.
    van der Bijl, Wouter
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Kotrschal, Alexander
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Buechel, Séverine D.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Kolm, Niclas
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Cognitive ability and antagonistic social competence: contest duration depends on loser’s brain sizeManuskript (preprint) (Annet vitenskapelig)
  • 1571.
    van der Bijl, Wouter
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Thyselius, Malin
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Kotrschal, Alexander
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Kolm, Niclas
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Brain size affects the behavioural response to predators in female guppies (Poecilia reticulata)2015Inngår i: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 282, nr 1812, s. 116-124, artikkel-id 20151132Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Large brains are thought to result from selection for cognitive benefits, but how enhanced cognition leads to increased fitness remains poorly understood. One explanation is that increased cognitive ability results in improved monitoring and assessment of predator threats. Here, we use male and female guppies (Poecilia reticulata), artificially selected for large and small brain size, to provide an experimental evaluation of this hypothesis. We examined their behavioural response as singletons, pairs or shoals of four towards a model predator. Large-brained females, but not males, spent less time performing predator inspections, an inherently risky behaviour. Video analysis revealed that large-brained females were further away from the model predator when in pairs but that they habituated quickly towards the model when in shoals of four. Males stayed further away from the predator model than females but again we found no brain size effect in males. We conclude that differences in brain size affect the female predator response. Large-brained females might be able to assess risk better or need less sensory information to reach an accurate conclusion. Our results provide experimental support for the general idea that predation pressure is likely to be important for the evolution of brain size in prey species.

  • 1572.
    van der Bijl, Wouter
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Tsuboi, Masahito
    Iwaniuk, Andrew N.
    Kolm, Niclas
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Prey-predator interactions and the evolution of bird brain morphologyManuskript (preprint) (Annet vitenskapelig)
  • 1573.
    van der Jeugd, Henk
    et al.
    University of Oxford, UK ; Evolutionary Biology Centre. Sweden.
    van der Veen, Ineke
    Department of Evolutionary Ecology, Max-Planck Institute for Limnology, Germany.
    Larsson, Kjell
    Gotland University, Sweden.
    Kin clustering in barnacle geese: familiarity or phenotype matching?2002Inngår i: Behavioral Ecology, ISSN 1045-2249, E-ISSN 1465-7279, Vol. 13, nr 6, s. 786-790Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We investigated the settling pattern of barnacle geese Branta leucopsis that returned to breed in their natal colony. Females nested close to their parents and sisters, but settling of males conformed to a random pattern. The apparent preference for breeding close to kin in females could be a by-product of extreme philopatry to the natal nest site. However, sisters also nested close to each other when settling on a different island than the one where their parents bred, pointing at a genuine preference for breeding close to kin. Females only nested close to sisters born in the same year (i.e., sisters that they had been in close contact with). This suggests that the clustering of female kin in barnacle geese does not result from phenotype matching. We did not detect any direct benefits of settling close to birth site or kin, but the analyses lacked power to detect small benefits of proximity to kin given the many other factors that may influence breeding success. Colonially breeding birds share characteristics that are generally believed to promote the evolution of cooperation, yet kin clustering and kin selection have been little studied in this group. Future research should be directed to studying the possible roles of kin clustering and kin selection in the evolution of coloniality.

  • 1574.
    van der Valk, Tom
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Durazo, Frida Lona
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi. Univ Toronto, Dept Anthropol, Mississauga, ON, Canada..
    Dalen, Love
    Swedish Museum Nat Hist, Dept Bioinformat & Genet, Stockholm, Sweden..
    Guschanski, Katerina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Whole mitochondrial genome capture from faecal samples and museum-preserved specimens2017Inngår i: Molecular Ecology Resources, ISSN 1755-098X, E-ISSN 1755-0998, Vol. 17, nr 6, s. e111-e121Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Population-scale molecular studies of endangered and cryptic species are often limited by access to high-quality samples. The use of noninvasively collected samples or museum-preserved specimens reduces the pressure on modern populations by removing the need to capture and handle live animals. However, endogenous DNA content in such samples is low, making shotgun sequencing a financially prohibitive approach. Here, we apply a target enrichment method to retrieve mitochondrial genomes from 65 museum specimens and 56 noninvasively collected faecal samples of two endangered great ape species, Grauer's gorilla and the eastern chimpanzee. We show that the applied method is suitable for a wide range of sample types that differ in endogenous DNA content, increasing the proportion of target reads to over 300-fold. By systematically evaluating biases introduced during target enrichment of pooled museum samples, we show that capture is less efficient for fragments shorter or longer than the baits, that the proportion of human contaminating reads increases postcapture although capture efficiency is lower for human compared to gorilla fragments with a gorilla-generated bait, and that the rate of jumping PCR is considerable, but can be controlled for with a double-barcoding approach. We succeed in capturing complete mitochondrial genomes from faecal samples, but observe reduced capture efficiency as sequence divergence increases between the bait and target species. As previously shown for museum specimens, we demonstrate here that mitochondrial genome capture from field-collected faecal samples is a robust and reliable approach for population-wide studies of nonmodel organisms.

  • 1575.
    van Hamelsveld, Sophie
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk biokemi och mikrobiologi.
    Studies on possible global suppressor mutations in the hisA gene of Salmonella enterica2018Rapport (Annet vitenskapelig)
    Abstract [en]

    Global suppressor mutations have recently been recognised as an important factor in enzyme evolution. These are mutations that compensate for deleterious mutations by stabilising the protein’s structure. Their implication in the development of resistance to antibiotics, including the ever-prevalent β-lactamase enzymes responsible for widespread resistance towards drugs such as ampicillin, has made global suppressors the focus of recent research. Model enzyme systems are often used to study how genes evolve in a laboratory system. In this project, the hisA gene of Salmonella enterica was studied; specifically, a set of previously-isolated mutations thought to represent global suppressors. Using an optimised method of λ Red Recombineering and techniques to measure the relative growth rate of bacteria, these experiments aimed to study possible compensatory mutations and understand how they affected fitness. In doing so we have found further mutations which appear to compensate for harmful mutations by reducing their fitness cost.

  • 1576. van Lieshout, E.
    et al.
    Svensson, P. Andreas
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Wong, B.B.M.
    Consequences of paternal care on pectoral fin allometry in a desert-dwelling fish2013Inngår i: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 67, nr 3, s. 513-518Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Positive static allometry is a scaling relationship where the relative size of traits covaries with adult body size. Traditionally, positive allometry is thought to result from either altered physiological requirements at larger body size or from strongly condition-dependent allocation under sexual selection. Yet, there are no theoretical reasons why positive allometry cannot evolve in fitness-related traits that are solely under the influence of natural selection. We investigated scaling and sexual dimorphism of a naturally selected trait, pectoral fin size, in comparison to a trait important in male–male combat, head width in natural populations of a fish, the desert goby Chlamydogobius eremius. Male desert gobies provide uniparental care and use their pectoral fins to fan the brood (often under hypoxic conditions); hence, larger fins are expected to be more efficient. Male pectoral fins do not appear to fulfil a signalling function in this species. We found that, for both pectoral fin size and head width, males exhibited positive allometric slopes and greater relative trait size (allometric elevation) than females. However, for head width, females also showed positive allometry, albeit to a lesser degree than males. Because fin locomotory function typically does not result in positive allometry, our findings indicate that other naturally selected uses, such as paternal care, can exaggerate trait scaling relationships.

  • 1577. VanBuren, Collin S.
    et al.
    Campione, Nicolas E.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Paleobiologi.
    Evans, David C.
    Head size, weaponry, and cervical adaptation: Testing craniocervical evolutionary hypotheses in Ceratopsia2015Inngår i: Evolution, ISSN 0014-3820, E-ISSN 1558-5646, Vol. 69, nr 7, s. 1728-1744Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    The anterior cervical vertebrae form the skeletal connection between the cranial and postcranial skeletons in higher tetrapods. As a result, the morphology of the atlas-axis complex is likely to be shaped by selection pressures acting on either the head or neck. The neoceratopsian (Reptilia:Dinosauria) syncervical represents one of the most highly modified atlas-axis regions in vertebrates, being formed by the complete coalescence of the three most anterior cervical vertebrae. In ceratopsids, the syncervical has been hypothesized to be an adaptation to support a massive skull, or to act as a buttress during intraspecific head-to-head combat. Here, we test these functional/adaptive hypotheses within a phylogenetic framework and critically examine the previously proposed methods for quantifying relative head size in the fossil record for the first time. Results indicate that neither the evolution of cranial weaponry nor large head size correlates with the origin of cervical fusion in ceratopsians, and we, therefore, reject both adaptive hypotheses for the origin of the syncervical. Anterior cervical fusion has evolved independently in a number of amniote clades, and further research on extant groups with this peculiar anatomy is needed to understand the evolutionary basis for cervical fusion in Neoceratopsia.

  • 1578.
    Varg, Javier Edo.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Host, its microbiota and their interactions2018Rapport (Annet vitenskapelig)
    Abstract [en]

    The development of sequencing technologies has advanced the field of host-associated microbiology by showing the huge diversity and functionality of the omnipresent microbes of all multicellular life. With these advances, new interesting questions have been raised with regards to microbial community composition, pollutants that can interact with the host microbial community, the factors that can affect the host microbial community and the processes that determine the enormous variety of the microbiota among hosts of the same species or genotype. However, conceptual disagreement regarding the ecology, genetics and evolutionary concepts regulating microbial diversity are frequently occurring in this field. Concepts such as symbiont, holobiont, and hologenome are generating discordances in the scientific community regarding microbial host associations and microbial communities. Then it is important to take into account the definitions and clarify the bases of these concepts: the holobiont refers to the host and their symbiotic microbes. Therefore, the hologenome are the genes of host plus the genes of their symbionts. However, the symbiont definition is wide open and when we use it at the holobiont level it can be misinterpreted as all microbes in a host. To separate symbionts from non-symbionts, it is necessary to search at the functional level for the emergence or enhancement of traits at the holobiont level. For that reason, not all of the microbiota are symbionts and, therefore the holobiont should only include the host and all the microbial symbionts that inhabit it. Consequently, host-associated microbes are part of the amalgam in the complex organisation of an organism and can also be explained by ecological associations. Understanding these complex interactions between host and its microbiota can, for instance, give us insight into how this community can influence the host’s regulatation of pollutants as stress factors. More important, to understand synergistic effects of pollutants such as microplastics and metals on the host and their microorganisms, constitute one of the new frontiers in toxicology. Finally, it is important to take into account how stress factors such as competition, environmental changes, pollution, and diet can influence the fitness, genome dynamics and diversification between organisms. 

  • 1579.
    Vargas, Alexander O
    et al.
    Laboratorio de Ontogenia y Filogenia, Departamento de Biología, Facultad de Ciencias Universidad de Chile, Las Palermas, Ñuñoa, Santiago, Chile.
    Krabichler, Quirin
    TUM School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany.
    Guerrero-Bosagna, Carlos
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten.
    An Epigenetic Perspective on the Midwife Toad Experiments of Paul Kammerer (1880-1926)2017Inngår i: Journal of Experimental Zoology Part B: Molecular and Developmental Evolution, ISSN 1552-5007, E-ISSN 1552-5015, Vol. 328, nr 1-2, s. 179-192Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Paul Kammerer was the most outstanding neo-Lamarckian experimentalist of the early 20th century. He reported spectacular results in the midwife toad, including crosses of environmentally modified toads with normal toads, where acquired traits were inherited in Mendelian fashion. Accusations of fraud generated a great scandal, ending with Kammerer's suicide. Controversy reignited in the 1970s, when journalist Arthur Koestler argued against these accusations. Since then, others have argued that Kammerer's results, even if real, were not groundbreaking and could be explained by somatic plasticity, inadvertent selection, or conventional genetics. More recently, epigenetics has uncovered mechanisms by which inheritance can respond directly to environmental change, inviting a reanalysis of Kammerer's descriptions. Previous arguments for mere somatic plasticity have ignored the description of experiments showing heritable germ line modification. Alleged inadvertent selection associated with egg mortality can be discarded, since mortality decreased in a single generation, upon repeated exposures. The challenging implications did not escape the attention of Kammerer's noted contemporary, William Bateson, but he reacted with disbelief, thus encouraging fraud accusations. Nowadays, formerly puzzling phenomena can be explained by epigenetic mechanisms. Importantly, Kammerer described parent-of-origin effects, an effect of parental sex on dominance. Epigenetic mechanisms underlie these effects in genomic imprinting and experiments of transgenerational epigenetic inheritance. In the early 20th century, researchers had no reason to link them with the inheritance of acquired traits. Thus, the parent-of-origin effects in Kammerer's experiments specifically suggest authenticity. Ultimate proof should come from renewed experimentation. To encourage further research, we present a model of possible epigenetic mechanisms.

  • 1580.
    Varshney, Gaurav K.
    et al.
    NHGRI, Translat & Funct Genom Branch, NIH, Bethesda, MD 20892 USA..
    Zhang, Suiyuan
    NHGRI, Computat & Stat Genom Branch, NIH, Bethesda, MD 20892 USA..
    Pei, Wuhong
    NHGRI, Translat & Funct Genom Branch, NIH, Bethesda, MD 20892 USA..
    Adomako-Ankomah, Ashrifia
    NHGRI, Translat & Funct Genom Branch, NIH, Bethesda, MD 20892 USA..
    Fohtung, Jacob
    NHGRI, Translat & Funct Genom Branch, NIH, Bethesda, MD 20892 USA..
    Schaffer, Katherine
    NHGRI, Translat & Funct Genom Branch, NIH, Bethesda, MD 20892 USA..
    Carrington, Blake
    NHGRI, Zebrafish Core, Translat & Funct Genom Branch, NIH, Bethesda, MD 20892 USA..
    Maskeri, Anoo
    NHGRI, Translat & Funct Genom Branch, NIH, Bethesda, MD 20892 USA..
    Slevin, Claire
    NHGRI, Translat & Funct Genom Branch, NIH, Bethesda, MD 20892 USA..
    Wolfsberg, Tyra
    NHGRI, Computat & Stat Genom Branch, NIH, Bethesda, MD 20892 USA..
    Ledin, Johan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi.
    Sood, Raman
    NHGRI, Zebrafish Core, Translat & Funct Genom Branch, NIH, Bethesda, MD 20892 USA..
    Burgess, Shawn M.
    NHGRI, Translat & Funct Genom Branch, NIH, Bethesda, MD 20892 USA..
    CRISPRz: a database of zebrafish validated sgRNAs2016Inngår i: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 44, nr D1, s. D822-D826Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    CRISPRz (http://research.nhgri.nih.gov/CRISPRz/) is a database of CRISPR/Cas9 target sequences that have been experimentally validated in zebrafish. Programmable RNA-guided CRISPR/Cas9 has recently emerged as a simple and efficient genome editing method in various cell types and organisms, including zebrafish. Because the technique is so easy and efficient in zebrafish, the most valuable asset is no longer a mutated fish (which has distribution challenges), but rather a CRISPR/Cas9 target sequence to the gene confirmed to have high mutagenic efficiency. With a highly active CRISPR target, a mutant fish can be quickly replicated in any genetic background anywhere in the world. However, sgRNA's vary widely in their activity and models for predicting target activity are imperfect. Thus, it is very useful to collect in one place validated CRISPR target sequences with their relative mutagenic activities. A researcher could then select a target of interest in the database with an expected activity. Here, we report the development of CRISPRz, a database of validated zebrafish CRISPR target sites collected from published sources, as well as from our own in-house large-scale mutagenesis project. CRISPRz can be searched using multiple inputs such as ZFIN IDs, accession number, UniGene ID, or gene symbols from zebrafish, human and mouse.

  • 1581.
    Vasconcelos, Paula
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Multidimensional Adaptive Dynamics and evolutionary diversification2017Rapport (Annet vitenskapelig)
  • 1582.
    Vaskaninova, Valeria
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi. Charles Univ Prague, Fac Sci, Inst Geol & Palaeontol, Prague, Czech Republic..
    Ahlberg, Per E.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi.
    Unique diversity of acanthothoracid placoderms (basal jawed vertebrates) in the Early Devonian of the Prague Basin, Czech Republic: A new look at Radotina and Holopetalichthys2017Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, nr 4, artikkel-id e0174794Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The taxonomy of Early Devonian placoderm material from the Lochkovian and Pragian of the Prague basin, previously attributed to the genera Radotina and Holopetalichthys, is revised. The Pragian species Radotina tesselata Gross 1958 shares detailed similarities with the holotype of the Lochkovian Radotina kosorensis Gross 1950, which is also the holotype of the genus; the assignation of both species to Radotina is supported. However, the Lochkovian material previously attributed to Radotina kosorensis also contains two unrecognised taxa, distinguishable from Radotina at the generic level: these are here named Tlamaspis and Sudaspis. The disputed genus Holopetalichthys, synonymised with Radotina by some previous authors, is shown to be valid. Furthermore, whereas Radotina, Tlamaspis and Sudaspis can all be assigned to the group Acanthothoracii, on the basis of several features including possession of a projecting prenasal region of the endocranium, Holopetalichthys lacks such a region and is probably not an acanthothoracid. Skull roof patterns and other aspects of morphology vary greatly between these taxa. Radotina has a substantially tesselated skull roof, whereas the skull roofs of Tlamaspis and Holopetalichthys appear to lack tesserae altogether. Tlamaspis has an extremely elongated facial region and appears to lack a premedian plate. Sudaspis has a long prenasal region, but unlike Tlamaspis the postnasal face is not elongated. Past descriptions of the braincase of ' Radotina' and the skull roofs of ' Radotina' and ' Holopetalichthys' incorporate data from more than one taxon, giving rise to spurious characterisations including an apparently extreme degree of skull roof variability. These descriptions should all be disregarded.

  • 1583.
    Vavrek, Matthew J.
    et al.
    Philip J. Currie Dinosaur Museum.
    Evans, David C.
    Royal Ontario Museum.
    Braman, Dennis R.
    Canadian Journal of Earth Sciences.
    Campione, Nicolas E.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper.
    Zazula, Grant D.
    Government of Yukon.
    A Paleogene flora from the upper Bonnet Plume Formation of northeast Yukon Territory, Canada2012Inngår i: Canadian journal of earth sciences (Print), ISSN 0008-4077, E-ISSN 1480-3313, Vol. 49, nr 3, s. 547-558Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Palaeontological exploration of the Bonnet Plume Basin in northwestern Yukon Territory, Canada, has revealed a Late Paleocene to Early Eocene macrofloral assemblage from a channel fill deposit. The flora is typified by cosmopolitan taxa and dominated by deciduous angiosperms, with the notable presence of ZizyphoidesEttingshausenia, and Corylites. Floras with a similar composition are known from Late Cretaceous through Early Eocene deposits in Alaska and the Canadian Arctic Archipelago, where they have been interpreted as evidence for warm, equable temperatures. This collection represents the most diverse known Paleogene plant macrofossil assemblage from the Yukon Territory and helps to expand our knowledge of ancient high-latitude floras.

  • 1584.
    Videvall, Elin
    et al.
    Lund Univ, Mol Ecol & Evolut Lab, Dept Biol, Lund, Sweden..
    Sletvold, Nina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Hagenblad, Jenny
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution. Linkoping Univ, IFM Biol, Linkoping, Sweden..
    Ågren, Jon
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Hansson, Bengt
    Lund Univ, Mol Ecol & Evolut Lab, Dept Biol, Lund, Sweden..
    Strong Maternal Effects on Gene Expression in Arabidopsis lyrata Hybrids2016Inngår i: Molecular biology and evolution, ISSN 0737-4038, E-ISSN 1537-1719, Vol. 33, nr 4, s. 984-994Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hybridization between populations or species can have pronounced fitness consequences. Yet little is known about how hybridization affects gene regulation. Three main models have been put forward to explain gene expression patterns in hybrids: additive, dominance, or parental effects. Here, we use high throughput RNA-sequencing to examine the extent to which hybrid gene expression follows predictions by each of the three models. We performed a reciprocal crossing experiment between two differentiated populations of the perennial herb Arabidopsis lyrata and sequenced RNA in rosette leaves of 12-week-old plants grown in greenhouse conditions. The two parental populations had highly differentiated gene expression patterns. In hybrids, a majority of genes showed intermediate expression relative to that of their parental populations (i.e., additive effects), but expression was frequently more similar to the maternal than to their paternal population (i.e., maternal effects). Allele-specific expression analyses showed that in the vast majority of cases, genes with pronounced maternal effect expressed both the maternal and the paternal allele. Maternal effects on hybrid gene expression have rarely been documented previously and our study suggests it could be more common than previously assumed. Whether the maternal effect on gene expression persists to later life-stages, and whether the variation in gene expression is manifested in other aspects of the phenotype, remain to be elucidated. Our findings are relevant for understanding the consequences of outbreeding and hybridization and open up several questions for future studies.

  • 1585.
    Viding, Essi
    et al.
    Department of Psychology, University College London, Gower Street, London, UK; Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King’s College London, London, UK.
    Larsson, Henrik
    Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
    Jones, Alice P.
    Department of Psychology, University College London, Gower Street, London, UK; Social, Genetic, and Developmental Psychiatry Centre, Institute of Psychiatry, King’s College London, London, UK.
    Quantitative genetic studies of antisocial behaviour2008Inngår i: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, Vol. 363, nr 1503, s. 2519-2527Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper will broadly review the currently available twin and adoption data on antisocial behaviour (AB). It is argued that quantitative genetic research can make a significant contribution to further the understanding of how AB develops. Genetically informative study designs are particularly useful for investigating several important questions such as whether: the heritability estimates vary as a function of assessment method or gender; the relative importance of genetic and environmental influences varies for different types of AB; the environmental risk factors are truly environmental; and genetic vulnerability influences susceptibility to environmental risk. While the current data are not yet directly translatable for prevention and treatment programmes, quantitative genetic research has concrete translational potential. Quantitative genetic research can supplement neuroscience research in informing about different subtypes of AB, such as AB coupled with callous-unemotional traits. Quantitative genetic research is also important in advancing the understanding of the mechanisms by which environmental risk operates.

  • 1586.
    Vijay, Nagarjun
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Bossu, Christen M.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab. Stockholm Univ, Dept Zool Populat Genet, SE-10691 Stockholm, Sweden..
    Poelstra, Jelmer W.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Weissensteiner, Matthias H.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Suh, Alexander
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Kryukov, Alexey P.
    Russian Acad Sci, Inst Biol & Soil Sci, Far East Branch, Lab Evolutionary Zool & Genet, Vladivostok 690022, Russia..
    Wolf, Jochen B. W.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab. Univ Munich, Div Evolutionary Biol, Grosshaderner St 2, D-82152 Planegg Martinsried, Germany..
    Evolution of heterogeneous genome differentiation across multiple contact zones in a crow species complex2016Inngår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 7, artikkel-id 13195Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Uncovering the genetic basis of species diversification is a central goal in evolutionary biology. Yet, the link between the accumulation of genomic changes during population divergence and the evolutionary forces promoting reproductive isolation is poorly understood. Here, we analysed 124 genomes of crow populations with various degrees of genome-wide differentiation, with parallelism of a sexually selected plumage phenotype, and ongoing hybridization. Overall, heterogeneity in genetic differentiation along the genome was best explained by linked selection exposed on a shared genome architecture. Superimposed on this common background, we identified genomic regions with signatures of selection specific to independent phenotypic contact zones. Candidate pigmentation genes with evidence for divergent selection were only partly shared, suggesting context-dependent selection on a multigenic trait architecture and parallelism by pathway rather than by repeated single-gene effects. This study provides insight into how various forms of selection shape genome-wide patterns of genomic differentiation as populations diverge.

  • 1587.
    Viklund, Johan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär evolution.
    Phylogenomics of Oceanic Bacteria2013Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The focus of this thesis has been the phylogenomics and evolution of the Alphaproteobacteria. This is a very diverse group which encompasses bacteria from intraceullar parasites, such as the Rickettsiales, to freeliving bacteria such as the most abundant bacteria on earth, the SAR11. The genome sizes of the Alphaproteobacteria range between 1 Mb and 10 Mb. This group is also connected to the origin of the mitochondria.

    Several studies have placed the SAR11 clade together with the Rickettsiales and mitochon- dria. Here I have shown that this placement is an artifact of compositional heterogeneity. When choosing genes or sites less affected by heterogeneity we find that the SAR11-clade instead groups with free-living alphaproteobacteria. Gene-content analysis showed that SAR11 was missing several genes for recombination and DNA-repair. The relationships within the SAR11- clade has also been examined and questioned. Specifically, we found no support for placing the taxon referred to as HIMB59 within the SAR11. Ocean metagenomes have been investigated to determine whether the SAR11-clade is a potential relative of the mitochondria. No such relationship was found.

    Further I have shown how important it is to take the phylogenetic relationships into account when doing statistical analyzes of genomes.

    The evolution of LD12, the freshwater representative of SAR11, was investigated. Phyloge- nies and synonymous substitution frequencies showed the presence of three distinct subclades within LD12. The recombination to mutation rate was found to be extremely low. This is re- markable in light of the very high rate in the oceanic SAR11. This is may be due to adaptation to a more specialized niche.

    Finally we have compared structure-based and sequence-based methods for orthology pre- diction. A high fraction of the orfan proteins were predicted to code for intrinsically disordered proteins.

    Many phylogenetic methods are sensitive to heterogeneity and this needs to be taken into ac- count when doing phylogenies. There have been at least three independent genome reductions in the Alphaproteobacteria. The frequency of recombination differ greatly between freshwater and oceanic SAR11. Forces affecting the size of bacterial genomes and mechanisms of evolu- tionary change depend on the environmental context.

     

  • 1588.
    Viklund, Johan
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär evolution.
    Andersson, Siv
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär evolution.
    On the importance of taxonomically representative groups for the inference of adaptive traits in surface oceanic bacteriaManuskript (preprint) (Annet vitenskapelig)
  • 1589.
    Viklund, Johan
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär evolution. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Ettema, Thijs
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär evolution. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Andersson, Siv G. E.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär evolution. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Independent Genome Reduction and Phylogenetic Reclassification of the Oceanic SAR11 Clade2011Inngår i: Molecular biology and evolution, ISSN 0737-4038, E-ISSN 1537-1719, Vol. 29, nr 2, s. 599-615Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The SAR11 clade, here represented by Candidatus Pelagibacter ubique, is the most successful group of bacteria in the upper surface waters of the oceans. In contrast to previous studies that have associated the 1.3 Mb genome of Ca. Pelagibacter ubique with the less than 1.5 Mb genomes of the Rickettsiales, our phylogenetic analysis suggests that Ca. Pelagibacter ubique is most closely related to soil and aquatic Alphaproteobacteria with large genomes. This implies that the SAR11 clade and the Rickettsiales have undergone genome reduction independently. A gene flux analysis of 46 representative alphaproteobacterial genomes indicates the loss of more than 800 genes in each of Ca. Pelagibacter ubique and the Rickettsiales. Consistent with their different phylogenetic affiliations, the pattern of gene loss differs with a higher loss of genes for repair and recombination processes in Ca. Pelagibacter ubique as compared with a more extensive loss of genes for biosynthetic functions in the Rickettsiales. Some of the lost genes in Ca. Pelagibacter ubique, such as mutLS, recFN, and ruvABC, are conserved in all other alphaproteobacterial genomes including the small genomes of the Rickettsiales. The mismatch repair genes mutLS are absent from all currently sequenced SAR11 genomes and also underrepresented in the global ocean metagenome data set. We hypothesize that the unique loss of genes involved in repair and recombination processes in Ca. Pelagibacter ubique has been driven by selection and that this helps explain many of the characteristics of the SAR11 population, such as the streamlined genomes, the long branch lengths, the high recombination frequencies, and the extensive sequence divergence within the population.

  • 1590.
    Viklund, Johan
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär evolution. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Martijn, Joran
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär evolution. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Ettema, Thijs
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär evolution. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Andersson, Siv
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär evolution. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Comparative and Phylogenomic Evidence that the Alphaproteobacterium HIMB59 is not a Member of the Oceanic SAR11 Clade2013Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, nr 11, s. e78858-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    SAR11 is a globally abundant group of Alphaproteobacteria in the oceans that is taxonomically not well defined. It has been suggested SAR11 should be classified into the novel order Pelagibacterales. Features such as conservation of gene content and synteny have been taken as evidence that also the divergent member HIMB59 should be included in the order. However, this proposition is controversial since phylogenetic analyses have questioned the monophyly of this grouping. Here, we performed phylogenetic analyses and reinvestigated the genomic similarity of SAR11 and HIMB59. Our phylogenetic analysis confirmed that HIMB59 is not a sister group to the other SAR11 strains. By placing the comparison in the context of the evolution of the Alphaproteobacteria, we found that none of the measures of genomic similarity supports a clustering of HIMB59 and SAR11 to the exclusion of other Alphaproteobacteria. First, pairwise sequence similarity measures for the SAR11 and HIMB59 genomes were within the range observed for unrelated pairs of Alphaproteobacteria. Second, pairwise comparisons of gene contents revealed a higher similarity of SAR11 to several other alphaproteobacterial genomes than to HIMB59. Third, the SAR11 genomes are not more similar in gene order to the HIMB59 genome than what they are to several other alphaproteobacterial genomes. Finally, in contrast to earlier reports, we observed no sequence similarity between the hypervariable region HVR2 in the SAR11 genomes and the region located at the corresponding position in the HIMB59 genome. Based on these observations, we conclude that the alphaproteobacterium HIMB59 is not monophyletic with the SAR11 strains and that genome streamlining has evolved multiple times independently in Alphaproteobacteria adapted to the upper surface waters of the oceans.

  • 1591. Visram, Shakil
    et al.
    Yang, Ming-Che
    Pillay, Ruby Moothien
    Said, Sadri
    Henriksson, Oskar
    Södertörns högskola.
    Grahn, Mats
    Chen, Chaolun Allen
    Genetic connectivity and historical demography of the blue barred parrotfish (Scarus ghobban) in the western Indian Ocean2010Inngår i: Marine Biology, ISSN 0025-3162, E-ISSN 1432-1793, Vol. 157, nr 7, s. 1475-1487Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Studies on genetic connectivity are essential for the design of management strategies for coral reef fisheries. In this study we used a mitochondrial DNA marker to investigate population structure of the reef-associated parrotfish, Scarus ghobban, from four countries, Kenya, Mauritius, Seychelles and Tanzania, in the western Indian Ocean. We obtained nucleotide sequences of the mitochondrial control region for 117 individuals. Measures of haplotype diversity were relatively high. Pairwise population differentiation (F (ST)) was low, but not always non-significant. Analysis of molecular variance (AMOVA) showed genetic differentiation between groups, when the data was partitioned into two groups consisting of samples from Mauritius and Tanzania in one group, and samples from Kenya and Seychelles in another group. Direction of gene flow was estimated using a Bayesian approach. Migration was sometimes asymmetric or directional, coinciding with the flow of major oceanic and coastal currents in the region. Mismatch distributions, based on the observed number of differences among haplotype pairs, produced a unimodal distribution, indicative of recent demographic expansion. Phylogenetic analyses revealed three clades without any geographic structure, suggesting recent migration between historically isolated lineages. We reconstructed the historical demography of S. ghobban and examined it in the context of Pleistocene climate stages and changes in relative sea level. Overall, these results showed that populations of S. ghobban are genetically diverse and have relatively high gene flow, with some genetic structuring in the western Indian Ocean.

  • 1592.
    Voeten, Dennis F. A. E.
    et al.
    European Synchrotron Radiat Facil, 71 Ave Martyrs,CS-40220, F-38043 Grenoble, France.;Palacky Univ, Dept Zool, 17 Listopadu 50, Olomouc 77146, Czech Republic.;Palacky Univ, Lab Ornithol, 17 Listopadu 50, Olomouc 77146, Czech Republic..
    Cubo, Jorge
    Sorbonne Univ, CNRS INSU, Inst Sci Terre Paris, ISTeP UMR 7193, F-75005 Paris, France..
    de Margerie, Emmanuel
    Univ Rennes 1, Univ Caen Normandie, CNRS, Lab Ethol Anim & Humaine, 263 Ave Gen Leclerc, F-35042 Rennes, France..
    Roeper, Martin
    Burgermeister Muller Museum, Bahnhofstr 8, D-91807 Solnhofen, Germany.;Bayerische Staatssammlung Palaontol & Geol, Richard Wagner Str 10, D-80333 Munich, Germany..
    Beyrand, Vincent
    European Synchrotron Radiat Facil, 71 Ave Martyrs,CS-40220, F-38043 Grenoble, France.;Palacky Univ, Dept Zool, 17 Listopadu 50, Olomouc 77146, Czech Republic.;Palacky Univ, Lab Ornithol, 17 Listopadu 50, Olomouc 77146, Czech Republic..
    Bures, Stanislav
    Palacky Univ, Dept Zool, 17 Listopadu 50, Olomouc 77146, Czech Republic.;Palacky Univ, Lab Ornithol, 17 Listopadu 50, Olomouc 77146, Czech Republic..
    Tafforeau, Paul
    European Synchrotron Radiat Facil, 71 Ave Martyrs,CS-40220, F-38043 Grenoble, France..
    Sanchez, Sophie
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Evolution och utvecklingsbiologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab. European Synchrotron Radiat Facil, 71 Ave Martyrs,CS-40220, F-38043 Grenoble, France.
    Wing bone geometry reveals active flight in Archaeopteryx2018Inngår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 9, artikkel-id 923Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Archaeopteryx is an iconic fossil taxon with feathered wings from the Late Jurassic of Germany that occupies a crucial position for understanding the early evolution of avian flight. After over 150 years of study, its mosaic anatomy unifying characters of both non-flying dinosaurs and flying birds has remained challenging to interpret in a locomotory context. Here, we compare new data from three Archaeopteryx specimens obtained through phase-contrast synchrotron microtomography to a representative sample of archosaurs employing a diverse array of locomotory strategies. Our analyses reveal that the architecture of Archaeopteryx's wing bones consistently exhibits a combination of cross-sectional geometric properties uniquely shared with volant birds, particularly those occasionally utilising short-distance flapping. We therefore interpret that Archaeopteryx actively employed wing flapping to take to the air through a more anterodorsally posteroventrally oriented flight stroke than used by modern birds. This unexpected outcome implies that avian powered flight must have originated before the latest Jurassic.

  • 1593.
    Vogan, Aaron
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Systematisk biologi.
    Svedberg, Jesper
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Systematisk biologi.
    Grudzinska-Sterno, Magdalena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Systematisk biologi.
    Johannesson, Hanna
    Meiotic drive is associated with reproductive isolation in NeurosporaManuskript (preprint) (Annet vitenskapelig)
  • 1594.
    Vogel, David
    et al.
    Univ Toulouse, CNRS, CRCA, Toulouse, France..
    Nicolis, Stamatios C.
    Uppsala Univ, Dept Math, S-75238 Uppsala, Sweden..
    Perez-Escudero, Alfonso
    Univ Toulouse, CNRS, LAPLACE, Toulouse, France.;CSIC, Cajal Inst, Madrid, Spain..
    Nanjundiah, Vidyanand
    Ctr Human Genet, Bangalore 560100, Karnataka, India..
    Sumpter, David J. T.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Matematiska institutionen.
    Dussutour, Audrey
    Univ Toulouse, CNRS, CRCA, Toulouse, France..
    Phenotypic variability in unicellular organisms: from calcium signalling to social behaviour2015Inngår i: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 282, nr 1819, artikkel-id 20152322Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Historically, research has focused on the mean and often neglected the variance. However, variability in nature is observable at all scales: among cells within an individual, among individuals within a population and among populations within a species. A fundamental quest in biology now is to find the mechanisms that underlie variability. Here, we investigated behavioural variability in a unique unicellular organism, Physarum polycephalum. We combined experiments and models to show that variability in cell signalling contributes to major differences in behaviour underpinning some aspects of social interactions. First, following thousands of cells under various contexts, we identified distinct behavioural phenotypes: 'slow-regular-social', 'fast-regular-social' and 'fast-irregular-asocial'. Second, coupling chemical analysis and behavioural assays we found that calcium signalling is responsible for these behavioural phenotypes. Finally, we show that differences in signalling and behaviour led to alternative social strategies. Our results have considerable implications for our understanding of the emergence of variability in living organisms.

  • 1595.
    von Euler, Tove
    et al.
    Stockholm University, Department of Ecology, Environment and Plant Sciences.
    Madec, Camille
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Ågren, Jon
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Växtekologi och evolution.
    Ehrlén, Johan
    Stockholm University, Department of Ecology, Environment and Plant Sciences.
    A demographic assessment of local adaptation in a grassland perennial herbManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Habitat heterogeneity in abiotic and biotic factors drives the evolution of adaptive population differentiation. Assessments of local adaptation among populations of perennial plants are commonly based on estimates of one or a few fitness components in reciprocal transplant experiments. However, natural selection does not act on fitness components but on life-time fitness, and local adaptation should therefore ideally be assessed based on integrated measures of the performance during the entire life cycle. We transplanted seedlings and adult plants reciprocally among four populations of the perennial herb Primula farinosa differing in abiotic and biotic conditions on the island of Öland, SE Sweden. We recorded survival, growth, flowering and fruit production during three consecutive years (2010-2012) and used integral projection models to quantify variation in total fitness, estimated as population growth rate. Transplant site had large effects on most aspects of plant performance, and the effects of population of origin on survival, growth, flowering propensity and fruit production varied among sites for several year × cohort combinations. However, no evidence of local adaptation, expressed through single fitness components or total fitness, was found. The results suggest that populations of P. farinosa differ genetically in traits influencing fitness, but these differences do not match current selection regimes. This study provides a template for how reciprocal transplant experiments can be combined with long-term demographic studies and population models to assess local adaptation in long-lived species based on estimates of total fitness.

  • 1596. von Rönn, J. A. C.
    et al.
    Harrod, C.
    Bensch, S.
    Wolf, Jochen
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Transcontinental migratory connectivity predicts parasite prevalence in breeding populations of the European barn swallow2015Inngår i: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 28, nr 3, s. 535-546Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Parasites exert a major impact on the eco-evolutionary dynamics of their hosts and the associated biotic environment. Migration constitutes an effective means for long-distance invasions of vector-borne parasites and promotes their rapid spread. Yet, ecological and spatial information on population-specific host-parasite connectivity is essentially lacking. Here, we address this question in a system consisting of a transcontinental migrant species, the European barn swallow (Hirundo rustica) which serves as a vector for avian endoparasites in the genera Plasmodium, Haemoproteus andLeucocytozoon. Using feather stable isotope ratios as geographically informative markers, we first assessed migratory connectivity in the host: Northern European breeding populations predominantly overwintered in dry, savannah-like habitats in Southern Africa, whereas Southern European populations were associated with wetland habitats in Western Central Africa. Wintering areas of swallows breeding in Central Europe indicated a migratory divide with both migratory programmes occurring within the same breeding population. Subsequent genetic screens of parasites in the breeding populations revealed a link between the host's migratory programme and its parasitic repertoire: controlling for effects of local breeding location, prevalence of Africa-transmitted Plasmodium lineages was significantly higher in individuals overwintering in the moist habitats of Western Central Africa, even among sympatrically breeding individuals with different overwintering locations. For the rarer Haemoproteus parasites, prevalence was best explained by breeding location alone, whereas no clear pattern emerged for the least abundant parasite Leucocytozoon. These results have implications for our understanding of spatio-temporal host-parasite dynamics in migratory species and the spread of avian borne diseases.

  • 1597.
    von Rönn, Jan A. C.
    et al.
    Max Planck Inst Evolutionary Biol, Dept Evolutionary Genet, August Thienemann Str 2, D-24306 Plon, Germany.;Swiss Ornithol Inst, Seerose 1, CH-6204 Sempach, Switzerland..
    Shafer, Aaron B. A.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi.
    Wolf, Jochen B. W.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Evolutionsbiologi. Max Planck Inst Evolutionary Biol, Dept Evolutionary Genet, August Thienemann Str 2, D-24306 Plon, Germany..
    Disruptive selection without genome-wide evolution across a migratory divide2016Inngår i: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 25, nr 11, s. 2529-2541Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Transcontinental migration is a fascinating example of how animals can respond to climatic oscillation. Yet, quantitative data on fitness components are scarce, and the resulting population genetic consequences are poorly understood. Migratory divides, hybrid zones with a transition in migratory behaviour, provide a natural setting to investigate the micro-evolutionary dynamics induced by migration under sympatric conditions. Here, we studied the effects of migratory programme on survival, trait evolution and genome-wide patterns of population differentiation in a migratory divide of European barn swallows. We sampled a total of 824 individuals from both allopatric European populations wintering in central and southern Africa, respectively, along with two mixed populations from within the migratory divide. While most morphological characters varied by latitude consistent with Bergmann's rule, wing length co-varied with distance to wintering grounds. Survival data collected during a 5-year period provided strong evidence that this covariance is repeatedly generated by disruptive selection against intermediate phenotypes. Yet, selection-induced divergence did not translate into genome-wide genetic differentiation as assessed by microsatellites, mtDNA and >20 000 genome-wide SNP markers; nor did we find evidence of local genomic selection between migratory types. Among breeding populations, a single outlier locus mapped to the BUB1 gene with a role in mitotic and meiotic organization. Overall, this study provides evidence for an adaptive response to variation in migration behaviour continuously eroded by gene flow under current conditions of non-assortative mating. It supports the theoretical prediction that population differentiation is difficult to achieve under conditions of gene flow despite measurable disruptive selection.

  • 1598.
    Vowles, Tage
    et al.
    Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden; Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden.
    Lindwall, Frida
    Terrestrial Ecology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Center for Permafrost, Department of Geoscience and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark.
    Ekblad, Alf
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Bahram, Mohammad
    Department of Organismal Biology, Uppsala University, Uppsala, Sweden; Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia.
    Furneaux, Brendan R.
    Department of Organismal Biology, Uppsala University, Uppsala, Sweden.
    Ryberg, Martin
    Department of Organismal Biology, Uppsala University, Uppsala, Sweden.
    Björk, Robert G.
    Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden; Gothenburg Global Biodiversity Centre, Gothenburg, Sweden.
    Complex effects of mammalian grazing on extramatrical mycelial biomass in the Scandes forest-tundra ecotone2018Inngår i: Ecology and Evolution, ISSN 2045-7758, E-ISSN 2045-7758, Vol. 8, nr 2, s. 1019-1030Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mycorrhizal associations are widespread in high-latitude ecosystems and are potentially of great importance for global carbon dynamics. Although large herbivores play a key part in shaping subarctic plant communities, their impact on mycorrhizal dynamics is largely unknown. We measured extramatrical mycelial (EMM) biomass during one growing season in 16-year-old herbivore exclosures and unenclosed control plots (ambient), at three mountain birch forests and two shrub heath sites, in the Scandes forest-tundra ecotone. We also used high-throughput amplicon sequencing for taxonomic identification to investigate differences in fungal species composition. At the birch forest sites, EMM biomass was significantly higher in exclosures (1.36 +/- 0.43g C/m(2)) than in ambient conditions (0.66 +/- 0.17g C/m(2)) and was positively influenced by soil thawing degree-days. At the shrub heath sites, there was no significant effect on EMM biomass (exclosures: 0.72 +/- 0.09g C/m(2); ambient plots: 1.43 +/- 0.94). However, EMM biomass was negatively related to Betula nana abundance, which was greater in exclosures, suggesting that grazing affected EMM biomass positively. We found no significant treatment effects on fungal diversity but the most abundant ectomycorrhizal lineage/cortinarius, showed a near-significant positive effect of herbivore exclusion (p=.08), indicating that herbivory also affects fungal community composition. These results suggest that herbivory can influence fungal biomass in highly context-dependent ways in subarctic ecosystems. Considering the importance of root-associated fungi for ecosystem carbon balance, these findings could have far-reaching implications.

  • 1599.
    Vreeburg, Sabine
    et al.
    Wageningen Univ, Plant Sci Grp, Genet Lab, NL-6700 AA Wageningen, Netherlands..
    Nygren, Kristiina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Systematisk biologi. Wageningen Univ, Plant Sci Grp, Genet Lab, NL-6700 AA Wageningen, Netherlands..
    Aanen, Duur K.
    Wageningen Univ, Plant Sci Grp, Genet Lab, NL-6700 AA Wageningen, Netherlands..
    Unholy marriages and eternal triangles: how competition in the mushroom life cycle can lead to genomic conflict2016Inngår i: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, Vol. 371, nr 1706, artikkel-id 20150533Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    In the vast majority of sexual life cycles, fusion between single-celled gametes is directly followed by nuclear fusion, leading to a diploid zygote and a lifelong commitment between two haploid genomes. Mushroom-forming basidiomycetes differ in two key respects. First, the multicellular haploid mating partners are fertilized in their entirety, each cell being a gamete that simultaneously can behave as a female, i.e. contributing the cytoplasm to a zygote by accepting nuclei, and a male gamete, i.e. only donating nuclei to the zygote. Second, after gamete union, the two haploid genomes remain separate so that the main vegetative stage, the dikaryon, has two haploid nuclei per cell. Only when the dikaryon produces mushrooms, do the nuclei fuse to enter a short diploid stage, immediately followed by meiosis and haploid spore formation. So in basidiomycetes, gamete fusion and genome mixing (sex) are separated in time. The 'living apart together' of nuclei in the dikaryon maintains some autonomy for nuclei to engage in a relationship with a different nucleus. We show that competition among the two nuclei of the dikaryon for such 'extramarital affairs' may lead to genomic conflict by favouring genes beneficial at the level of the nucleus, but deleterious at that of the dikaryon. This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'.

  • 1600. Wahlberg, Emma
    et al.
    Johanson, Kjell Arne
    The age, ancestral distribution and radiation of Chimarra (Trichoptera: Philopotamidae) using molecular methods2014Inngår i: Molecular Phylogenetics and Evolution, ISSN 1055-7903, E-ISSN 1095-9513, Vol. 79, s. 433-442Artikkel i tidsskrift (Fagfellevurdert)
    Abstract
29303132333435 1551 - 1600 of 1709
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