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  • 1.
    Aliashkevich, Alena
    et al.
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Schiffthaler, Bastian
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Cava, Felipe
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Genetic dissection of LD-transpeptidation in Agrobacterium tumefaciensManuscript (preprint) (Other academic)
  • 2. Apuli, Rami-Petteri
    et al.
    Bernhardsson, Carolina
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Schiffthaler, Bastian
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Robinson, Kathryn M
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Jansson, Stefan
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Street, Nathaniel
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Ingvarsson, Pär K.
    Inferring the Genomic Landscape of Recombination Rate Variation in European Aspen (Populus tremula)2020In: G3: Genes, Genomes, Genetics, E-ISSN 2160-1836, Vol. 10, no 1, p. 299-309Article in journal (Refereed)
    Abstract [en]

    The rate of meiotic recombination is one of the central factors determining genome-wide levels of linkage disequilibrium which has important consequences for the efficiency of natural selection and for the dissection of quantitative traits. Here we present a new, high-resolution linkage map for Populus tremula that we use to anchor approximately two thirds of the P. tremula draft genome assembly on to the expected 19 chromosomes, providing us with the first chromosome-scale assembly for P. tremula (Table 2). We then use this resource to estimate variation in recombination rates across the P. tremula genome and compare these results to recombination rates based on linkage disequilibrium in a large number of unrelated individuals. We also assess how variation in recombination rates is associated with a number of genomic features, such as gene density, repeat density and methylation levels. We find that recombination rates obtained from the two methods largely agree, although the LD-based method identifies a number of genomic regions with very high recombination rates that the map-based method fails to detect. Linkage map and LD-based estimates of recombination rates are positively correlated and show similar correlations with other genomic features, showing that both methods can accurately infer recombination rate variation across the genome. Recombination rates are positively correlated with gene density and negatively correlated with repeat density and methylation levels, suggesting that recombination is largely directed toward gene regions in P. tremula.

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  • 3.
    Bernhardsson, Carolina
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Science, Umeå, Sweden; Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Science, Uppsala, Sweden.
    Vidalis, Amaryllis
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Department of Population Genetics, Center of Life and Food Sciences Weihenstephan, Technische Universität München.
    Wang, Xi
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Science, Uppsala, Sweden.
    Scofield, Douglas
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Uppsala Multidisciplinary Center for Advanced Computational Science; Department of Ecology and Genetics: Evolutionary Biology, Uppsala University, Uppsala, Sweden.
    Schiffthaler, Bastian
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Baison, John
    Street, Nathaniel
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Garcia-Gil, M. Rosario
    Ingvarsson, Pär K.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Department of Plant Biology, Uppsala BioCenter, Swedish University of Agricultural Science, Uppsala, Sweden.
    An Ultra-Dense Haploid Genetic Map for Evaluating the Highly Fragmented Genome Assembly of Norway Spruce (Picea abies)2019In: G3: Genes, Genomes, Genetics, E-ISSN 2160-1836, Vol. 9, no 5, p. 1623-1632Article in journal (Refereed)
    Abstract [en]

    Norway spruce (Picea abies (L.) Karst.) is a conifer species of substanital economic and ecological importance. In common with most conifers, the P. abies genome is very large (similar to 20 Gbp) and contains a high fraction of repetitive DNA. The current P. abies genome assembly (v1.0) covers approximately 60% of the total genome size but is highly fragmented, consisting of >10 million scaffolds. The genome annotation contains 66,632 gene models that are at least partially validated (), however, the fragmented nature of the assembly means that there is currently little information available on how these genes are physically distributed over the 12 P. abies chromosomes. By creating an ultra-dense genetic linkage map, we anchored and ordered scaffolds into linkage groups, which complements the fine-scale information available in assembly contigs. Our ultra-dense haploid consensus genetic map consists of 21,056 markers derived from 14,336 scaffolds that contain 17,079 gene models (25.6% of the validated gene models) that we have anchored to the 12 linkage groups. We used data from three independent component maps, as well as comparisons with previously published Picea maps to evaluate the accuracy and marker ordering of the linkage groups. We demonstrate that approximately 3.8% of the anchored scaffolds and 1.6% of the gene models covered by the consensus map have likely assembly errors as they contain genetic markers that map to different regions within or between linkage groups. We further evaluate the utility of the genetic map for the conifer research community by using an independent data set of unrelated individuals to assess genome-wide variation in genetic diversity using the genomic regions anchored to linkage groups. The results show that our map is sufficiently dense to enable detailed evolutionary analyses across the P. abies genome.

  • 4. Creel, Scott
    et al.
    Spong, Göran
    Becker, Matthew
    Simukonda, Chuma
    Norman, Anita
    Schiffthaler, Bastian
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Chifunte, Clive
    Carnivores, competition and genetic connectivity in the Anthropocene2019In: Scientific Reports, E-ISSN 2045-2322, Vol. 9, article id 16339Article in journal (Refereed)
    Abstract [en]

    Current extinction rates are comparable to five prior mass extinctions in the earth's history, and are strongly affected by human activities that have modified more than half of the earth's terrestrial surface. Increasing human activity restricts animal movements and isolates formerly connected populations, a particular concern for the conservation of large carnivores, but no prior research has used high throughput sequencing in a standardized manner to examine genetic connectivity for multiple species of large carnivores and multiple ecosystems. Here, we used RAD SNP genotypes to test for differences in connectivity between multiple ecosystems for African wild dogs (Lycaon pictus) and lions (Panthera leo), and to test correlations between genetic distance, geographic distance and landscape resistance due to human activity. We found weaker connectivity, a stronger correlation between genetic distance and geographic distance, and a stronger correlation between genetic distance and landscape resistance for lions than for wild dogs, and propose a new hypothesis that adaptations to interspecific competition may help to explain differences in vulnerability to isolation by humans.

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  • 5.
    Hernandez, Sara B.
    et al.
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Alvarez, Laura
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS).
    Ritzl-Rinkenberger, Barbara
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Schiffthaler, Bastian
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Serrano, Alonso R.
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Cava, Felipe
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Genome-wide peptidoglycan profiling of Vibrio choleraeManuscript (preprint) (Other academic)
  • 6.
    Jokipii-Lukkari, Soile
    et al.
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Sveriges Lantbruksuniversitet, SE-901 83 Umeå, Sweden.
    Delhomme, Nicolas
    Schiffthaler, Bastian
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Mannapperuma, Chanaka
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Prestele, Jakob
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Nilsson, Ove
    Street, Nathaniel
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Tuominen, Hannele
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Transcriptional Roadmap to Seasonal Variation in Wood Formation of Norway Spruce2018In: Plant Physiology, ISSN 0032-0889, E-ISSN 1532-2548, Vol. 176, no 4, p. 2851-2870Article in journal (Refereed)
    Abstract [en]

    Seasonal cues influence several aspects of the secondary growth of tree stems, including cambial activity, wood chemistry, and transition to latewood formation. We investigated seasonal changes in cambial activity, secondary cell wall formation, and tracheid cell death in woody tissues of Norway spruce (Picea abies) throughout one seasonal cycle. RNA sequencing was performed simultaneously in both the xylem and cambium/phloem tissues of the stem. Principal component analysis revealed gradual shifts in the transcriptomes that followed a chronological order throughout the season. A notable remodeling of the transcriptome was observed in the winter, with many genes having maximal expression during the coldest months of the year. A highly coexpressed set of monolignol biosynthesis genes showed high expression during the period of secondary cell wall formation as well as a second peak in midwinter. This midwinter peak in expression did not trigger lignin deposition, as determined by pyrolysis-gas chromatography/mass spectrometry. Coexpression consensus network analyses suggested the involvement of transcription factors belonging to the ASYMMETRIC LEAVES2/LATERAL ORGAN BOUNDARIES and MYELOBLASTOSIS-HOMEOBOX families in the seasonal control of secondary cell wall formation of tracheids. Interestingly, the lifetime of the latewood tracheids stretched beyond the winter dormancy period, correlating with a lack of cell death-related gene expression. Our transcriptomic analyses combined with phylogenetic and microscopic analyses also identified the cellulose and lignin biosynthetic genes and putative regulators for latewood formation and tracheid cell death in Norway spruce, providing a toolbox for further physiological and functional assays of these important phase transitions.

  • 7. Laitinen, Teresa
    et al.
    Morreel, Kris
    Delhomme, Nicolas
    Gauthier, Adrien
    Schiffthaler, Bastian
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Nickolov, Kaloian
    Brader, Günter
    Lim, Kean-Jin
    Teeri, Teemu H.
    Street, Nathaniel R.
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Boerjan, Wout
    Kärkönen, Anna
    A Key Role for Apoplastic H2O2 in Norway Spruce Phenolic Metabolism2017In: Plant Physiology, ISSN 0032-0889, E-ISSN 1532-2548, Vol. 174, no 3, p. 1449-1475Article in journal (Refereed)
    Abstract [en]

    Apoplastic events such as monolignol oxidation and lignin polymerization are difficult to study in intact trees. To investigate the role of apoplastic hydrogen peroxide (H2O2) in gymnosperm phenolic metabolism, an extracellular lignin-forming cell culture of Norway spruce (Picea abies) was used as a research model. Scavenging of apoplastic H2O2 by potassium iodide repressed lignin formation, in line with peroxidases activating monolignols for lignin polymerization. Time-course analyses coupled to candidate substrate-product pair network propagation revealed differential accumulation of low-molecular-weight phenolics, including (glycosylated) oligolignols, (glycosylated) flavonoids, and proanthocyanidins, in lignin-forming and H2O2-scavenging cultures and supported that monolignols are oxidatively coupled not only in the cell wall but also in the cytoplasm, where they are coupled to other monolignols and proanthocyanidins. Dilignol glycoconjugates with reduced structures were found in the culture medium, suggesting that cells are able to transport glycosylated dilignols to the apoplast. Transcriptomic analyses revealed that scavenging of apoplastic H2O2 resulted in remodulation of the transcriptome, with reduced carbon flux into the shikimate pathway propagating down to monolignol biosynthesis. Aggregated coexpression network analysis identified candidate enzymes and transcription factors for monolignol oxidation and apoplastic H2O2 production in addition to potential H2O2 receptors. The results presented indicate that the redox state of the apoplast has a profound influence on cellular metabolism.

  • 8. Lin, Yao-Cheng
    et al.
    Wang, Jing
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Faculty of Biosciences, Norwegian University of Life Sciences, Ås, Norway.
    Delhomme, Nicolas
    Schiffthaler, Bastian
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Sundström, Görel
    Zuccolo, Andrea
    Nystedt, Björn
    Hvidsten, Torgeir R.
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    de la Torre, Amanda
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). School of Forestry, Northern Arizona University, Flagstaff, AZ.
    Cossu, Rosa M.
    Hoeppner, Marc P.
    Lantz, Henrik
    Scofield, Douglas G.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Department of Ecology and Genetics: Evolutionary Biology, Uppsala University, Sweden; Uppsala Multidisciplinary Center for Advanced Computational Science, Uppsala University, Sweden.
    Zamani, Neda
    Johansson, Anna
    Mannapperuma, Chanaka
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Robinson, Kathryn M.
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Mähler, Niklas
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Leitch, Ilia J.
    Pellicer, Jaume
    Park, Eung-Jun
    Van Montagu, Marc
    Van de Peer, Yves
    Grabherr, Manfred
    Jansson, Stefan
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Ingvarsson, Pär K.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Department of Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Street, Nathaniel R.
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Functional and evolutionary genomic inferences in Populus through genome and population sequencing of American and European aspen2018In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 115, no 46, p. E10970-E10978Article in journal (Refereed)
    Abstract [en]

    The Populus genus is one of the major plant model systems, but genomic resources have thus far primarily been available for poplar species, and primarily Populus trichocarpa (Torr. & Gray), which was the first tree with a whole-genome assembly. To further advance evolutionary and functional genomic analyses in Populus, we produced genome assemblies and population genetics resources of two aspen species, Populus tremula L. and Populus tremuloides Michx. The two aspen species have distributions spanning the Northern Hemisphere, where they are keystone species supporting a wide variety of dependent communities and produce a diverse array of secondary metabolites. Our analyses show that the two aspens share a similar genome structure and a highly conserved gene content with P. trichocarpa but display substantially higher levels of heterozygosity. Based on population resequencing data, we observed widespread positive and negative selection acting on both coding and noncoding regions. Furthermore, patterns of genetic diversity and molecular evolution in aspen are influenced by a number of features, such as expression level, coexpression network connectivity, and regulatory variation. To maximize the community utility of these resources, we have integrated all presented data within the PopGenIE web resource (PopGenIE.org).

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  • 9.
    Mannapperuma, Chanaka
    et al.
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Liu, H.
    Bel, M.
    Delhomme, Nicolas
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Serrano, A.
    Schiffthaler, Bastian
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Hvidsten, Torgeir R.
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Vandepoele, K.
    Ayllón-Benítez, A.
    Street, Nathaniel
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    PlantGenIE-PLAZA: integrating orthology into the PlantGenIE.org resource using the PLAZA pipeline2020Manuscript (preprint) (Other academic)
  • 10.
    Mähler, Niklas
    et al.
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Schiffthaler, Bastian
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Robinson, Kathryn M.
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Terebieniec, Barbara K.
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Vucak, Matej
    Mannapperuma, Chanaka
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Bailey, Mark
    Jansson, Stefan
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Hvidsten, Torgeir
    Street, Nathaniel R.
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Leaf shape in Populus tremula is a complex, omnigenic trait2020In: Ecology and Evolution, E-ISSN 2045-7758, Vol. 10, no 21, p. 11922-11940Article in journal (Refereed)
    Abstract [en]

    Leaf shape is a defining feature of how we recognize and classify plant species. Although there is extensive variation in leaf shape within many species, few studies have disentangled the underlying genetic architecture. We characterized the genetic architecture of leaf shape variation in Eurasian aspen (Populus tremula L.) by performing genome‐wide association study (GWAS) for physiognomy traits. To ascertain the roles of identified GWAS candidate genes within the leaf development transcriptional program, we generated RNA‐Seq data that we used to perform gene co‐expression network analyses from a developmental series, which is publicly available within the PlantGenIE resource. We additionally used existing gene expression measurements across the population to analyze GWAS candidate genes in the context of a population‐wide co‐expression network and to identify genes that were differentially expressed between groups of individuals with contrasting leaf shapes. These data were integrated with expression GWAS (eQTL) results to define a set of candidate genes associated with leaf shape variation. Our results identified no clear adaptive link to leaf shape variation and indicate that leaf shape traits are genetically complex, likely determined by numerous small‐effect variations in gene expression. Genes associated with shape variation were peripheral within the population‐wide co‐expression network, were not highly connected within the leaf development co‐expression network, and exhibited signatures of relaxed selection. As such, our results are consistent with the omnigenic model.

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  • 11. Ratke, Christine
    et al.
    Terebieniec, Barbara K.
    Department of Forest Genetics and Plant Physiology, SLU, Umeå Plant Science Centre (UPSC), Umeå, Sweden.
    Winestrand, Sandra
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Derba-Maceluch, Marta
    Department of Forest Genetics and Plant Physiology, SLU, Umeå Plant Science Centre (UPSC), Umeå, Sweden.
    Grahn, Thomas
    Schiffthaler, Bastian
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Ulvcrona, Thomas
    Ozparpucu, Merve
    Rüggeberg, Markus
    Lundqvist, Sven-Olof
    Street, Nathaniel
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Jönsson, Leif J.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Mellerowicz, Ewa J.
    Downregulating aspen xylan biosynthetic GT43 genes in developing wood stimulates growth via reprograming of the transcriptome2018In: New Phytologist, ISSN 0028-646X, Vol. 219, no 1, p. 230-245Article in journal (Refereed)
    Abstract [en]

    Xylan is one of the main compounds determining wood properties in hardwood species. The xylan backbone is thought to be synthesized by a synthase complex comprising two members of the GT43 family. We downregulated all GT43 genes in hybrid aspen (Populus tremulaxtremuloides) to understand their involvement in xylan biosynthesis.

    All three clades of the GT43 family were targeted for downregulation using RNA interference individually or in different combinations, either constitutively or specifically in developing wood.

    Simultaneous downregulation in developing wood of the B (IRX9) and C (IRX14) clades resulted in reduced xylan Xyl content relative to reducing end sequence, supporting their role in xylan backbone biosynthesis. This was accompanied by a higher lignocellulose saccharification efficiency. Unexpectedly, GT43 suppression in developing wood led to an overall growth stimulation, xylem cell wall thinning and a shift in cellulose orientation. Transcriptome profiling of these transgenic lines indicated that cell cycling was stimulated and secondary wall biosynthesis was repressed. We suggest that the reduced xylan elongation is sensed by the cell wall integrity surveying mechanism in developing wood.

    Our results show that wood-specific suppression of xylan-biosynthetic GT43 genes activates signaling responses, leading to increased growth and improved lignocellulose saccharification.

  • 12.
    Schiffthaler, Bastian
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Embracing the data flood: integrating diverse data to improve phenotype association discovery in forest trees2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Complex traits represent valuable research targets as many highly desirable properties of plants and animals (such as growth rate and height) fall into this group. However, associating biological markers with these traits is incredibly challenging, in part due to their small effect sizes. For the two species at the core of our research, European aspen (Populus tremula) and Norway spruce (Picea abies), association studies are even more challenging, primarily due to the fragmented state of their genome assemblies. These assemblies represent the gene space well, but poorly represented inter-genic regions hinder variant discovery and large scale association studies.

    In this thesis, I present my work to improve association discovery of complex traits in forest trees. Firstly, to overcome the issues with assembly fragmentation, I have created an updated version of the P. tremula genome, which is highly contiguous and anchored in full chromosomes. To calculate the dense linkage map required to order and orient the aspen assembly, I developed "BatchMap", a parallel implementation of linkage mapping software. BatchMap has been successfully applied to several dense linkage maps, including aspen and Norway spruce, and was essential to the progress in improving the aspen genome assembly. Further, I developed seidr, which represents a starting point in multi-layer, network-based systems biology, an analysis technique with promising prospects for complex trait association analysis. As a case study, I applied some of the methods developed to the analysis of leaf shape in natural populations of European aspen, a complex, omnigenic trait.

    The multi-layer model of systems biology and related analysis techniques offer promise in the analysis of complex traits, and this thesis represents a starting point toward an intricate, holistic model of systems biology that may help to unravel the overwhelmingly complicated nature of complex traits.

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  • 13.
    Schiffthaler, Bastian
    et al.
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Bernhardsson, Carolina
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Ingvarsson, Par K.
    Street, Nathaniel R.
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    BatchMap: A parallel implementation of the OneMap R package for fast computation of F-1 linkage maps in outcrossing species2017In: PLOS ONE, E-ISSN 1932-6203, Vol. 12, no 12, article id e0189256Article in journal (Refereed)
    Abstract [en]

    With the rapid advancement of high throughput sequencing, large numbers of genetic markers can be readily and cheaply acquired, but most current software packages for genetic map construction cannot handle such dense input. Modern computer architectures and server farms represent untapped resources that can be used to enable higher marker densities to be processed in tractable time. Here we present a pipeline using a modified version of OneMap that parallelizes over bottleneck functions and achieves substantial speedups for producing a high density linkage map (N = 20,000). Using simulated data we show that the outcome is as accurate as the traditional pipeline. We further demonstrate that there is a direct relationship between the number of markers used and the level of deviation between true and estimated order, which in turn impacts the final size of a genetic map.

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  • 14.
    Schiffthaler, Bastian
    et al.
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Kostadima, Myrto
    Delhomme, Nicolas
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Rustici, Gabriella
    Training in High-Throughput Sequencing: Common Guidelines to Enable Material Sharing, Dissemination, and Reusability2016In: PloS Computational Biology, ISSN 1553-734X, E-ISSN 1553-7358, Vol. 12, no 6, article id e1004937Article in journal (Refereed)
    Abstract [en]

    The advancement of high-throughput sequencing (HTS) technologies and the rapid development of numerous analysis algorithms and pipelines in this field has resulted in an unprecedentedly high demand for training scientists in HTS data analysis. Embarking on developing new training materials is challenging for many reasons. Trainers often do not have prior experience in preparing or delivering such materials and struggle to keep them up to date. A repository of curated HTS training materials would support trainers in materials preparation, reduce the duplication of effort by increasing the usage of existing materials, and allow for the sharing of teaching experience among the HTS trainers' community. To achieve this, we have developed a strategy for materials' curation and dissemination. Standards for describing training materials have been proposed and applied to the curation of existing materials. A Git repository has been set up for sharing annotated materials that can now be reused, modified, or incorporated into new courses. This repository uses Git; hence, it is decentralized and self-managed by the community and can be forked/built-upon by all users. The repository is accessible at http://bioinformatics.upsc.se/htmr.

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  • 15.
    Schiffthaler, Bastian
    et al.
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Robinson, Kathryn
    Lu, Hui
    Bernhardsson, Carolina
    Westman, Sara
    Rendon, Martha
    Delhomme, Nicolas
    Jenkins, Jerry
    Wang, Jing
    Mähler, Niklas
    Richau, Kerstin
    Albrectsen, Benedicte
    Park, Eung-Jun
    Schmutz, Jeremy
    Jansson, Stefan
    Ingvarsson, Pär
    Street, Nathaniel
    An improved genome assembly of the European aspen Populus tremulaManuscript (preprint) (Other academic)
  • 16.
    Schiffthaler, Bastian
    et al.
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Serrano, Alonso
    Delhomme, Nicolas
    Street, Nathaniel
    Enhanced ensemble gene networks in systems biologyManuscript (preprint) (Other academic)
  • 17.
    Schiffthaler, Bastian
    et al.
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Terebieniec, Barbara K
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Mähler, Niklas
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Robinson, Kathryn M
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Mannapperuma, Chanaka
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Jansson, Stefan
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Street, Nathaniel R
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    An integrated functional genomics and systems genetics analysis of leaf shape in Populus tremula Manuscript (preprint) (Other academic)
    Abstract [en]

    Leaf shape is an important component of our relationship with the living world, representing a defining feature of how we recognise and classify plant species. There is extensive variation in the form and function of leaves within and between species. In the current study we utilised variation in leaf shape represented among individuals of a collection of Eurasian aspen (Populus tremula L.) sampled across Sweden and the remarkable extent of heterophylly present to establish morphological, cellular and transcriptional developmental time lines. We performed gene expression network and phenotypical regression analyses to identify genes of central importance or that were highly predictive of shape and size phenotypes during leaf development using a systems biology approach. We complemented this developmental study with a genome wide association study of leaf shape variation to identify single nucleotide polymorphisms associated with leaf shape and size, their genomic context and the biological role of associated genes. We then compared these association candidate genes to differentially expressed genes between groups of genotypes with highly contrasting leaf shapes, also considering whether there were expression quantitative trait loci associated with the genes. We demonstrate that our developmental gene expression series captured known biology for homologs of functionally characterised Arabidopsis thaliana genes and biological processes of importance during leaf development. We identified genes of high importance from the developmental series and natural variation analyses. These included genes with characterised functions in leaf development in addition to many novel candidates. Our systems genetics approach identified numerous genes supported by the developmental time series, phenotypic and expression association mapping and differential expression between phenotypic extremes. As such, we describe a rich resource for directing future functional characterisation studies and a comprehensive data resource characterising the role of gene expression during leaf development in aspen.

  • 18.
    Schiffthaler, Bastian
    et al.
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    van Zalen, Elena
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Serrano, Alonso R.
    Department of Plant Physiology, Umeå Plant Science Center, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Street, Nathaniel
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Delhomme, Nicolas
    Department of Plant Physiology, Umeå Plant Science Center, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Seiðr: Efficient calculation of robust ensemble gene networks2023In: Heliyon, E-ISSN 2405-8440, Vol. 9, no 6, article id e16811Article in journal (Refereed)
    Abstract [en]

    Gene regulatory and gene co-expression networks are powerful research tools for identifying biological signal within high-dimensional gene expression data. In recent years, research has focused on addressing shortcomings of these techniques with regard to the low signal-to-noise ratio, non-linear interactions and dataset dependent biases of published methods. Furthermore, it has been shown that aggregating networks from multiple methods provides improved results. Despite this, few useable and scalable software tools have been implemented to perform such best-practice analyses. Here, we present Seidr (stylized Seiðr), a software toolkit designed to assist scientists in gene regulatory and gene co-expression network inference. Seidr creates community networks to reduce algorithmic bias and utilizes noise corrected network backboning to prune noisy edges in the networks.

    Using benchmarks in real-world conditions across three eukaryotic model organisms, Saccharomyces cerevisiae, Drosophila melanogaster, and Arabidopsis thaliana, we show that individual algorithms are biased toward functional evidence for certain gene-gene interactions. We further demonstrate that the community network is less biased, providing robust performance across different standards and comparisons for the model organisms.

    Finally, we apply Seidr to a network of drought stress in Norway spruce (Picea abies (L.) H. Krast) as an example application in a non-model species. We demonstrate the use of a network inferred using Seidr for identifying key components, communities and suggesting gene function for non-annotated genes.

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  • 19. Spitzer, Robert
    et al.
    Norman, Anita J.
    Konigsson, Helena
    Schiffthaler, Bastian
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Spong, Goran
    De novo discovery of SNPs for genotyping endangered sun parakeets (Aratinga solstitialis) in Guyana2020In: Conservation Genetics Resources, ISSN 1877-7252, E-ISSN 1877-7260, Vol. 12, p. 631-641Article in journal (Refereed)
    Abstract [en]

    Parrots (Psittaciformes) are among the most endangered groups of birds today and remain threatened by habitat loss and exploitation for the live bird trade. Under such conditions, reliable and non-invasive monitoring techniques are crucial for successful conservation measures. In this study, we developed a panel of 86 high quality SNPs for genotyping endangered sun parakeets (Aratinga solstitialis) in Guyana, which form one of the last known breeding populations of this South American species in the wild. Genotyping was tested on different types of samples (blood, feathers, feces, beak and cloacal swabs). While blood performed best, feathers and feces also yielded reliable results and could thus be used as non-invasive sources of DNA for future population monitoring. Discriminant Analysis of Principal Components (DAPC) on genotypes revealed that Guyanese sun parakeets clustered separately from other psittacine species as well as conspecifics from a captive population. A priori known first-order kinships were also adequately detected by the SNP panel. Using a series of experimental contaminations, we found that contamination from other psittacine species and slight contamination ( 10%) from conspecifics did not prevent successful genotyping and recognition of individuals. We show that instances of higher conspecific contamination ( 50%) can be detected through an increased level of heterozygosity that falls outside the distribution of uncontaminated samples.

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  • 20.
    Sullivan, Alexis R.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Eldfjell, Yrin
    Schiffthaler, Bastian
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Plant Physiology.
    Delhomme, Nicolas
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Asp, Torben
    Hebelstrup, Kim H.
    Keech, Olivier
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Öber, Lisa
    Møller, Max
    Arvestad, Lars
    Street, Nathaniel
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Wang, Xiao-Ru
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    The Mitogenome of Norway Spruce and a Reappraisal of Mitochondrial Recombination in Plants2020In: Genome Biology and Evolution, ISSN 1759-6653, E-ISSN 1759-6653, Vol. 12, no 1, p. 3586-3598Article in journal (Refereed)
    Abstract [en]

    Plant mitogenomes can be difficult to assemble because they are structurally dynamic and prone to intergenomic DNA transfers, leading to the unusual situation where an organelle genome is far outnumbered by its nuclear counterparts. As a result, comparative mitogenome studies are in their infancy and some key aspects of genome evolution are still known mainly from pregenomic, qualitative methods. To help address these limitations, we combined machine learning and in silico enrichment of mitochondrial-like long reads to assemble the bacterial-sized mitogenome of Norway spruce (Pinaceae: Picea abies). We conducted comparative analyses of repeat abundance, intergenomic transfers, substitution and rearrangement rates, and estimated repeat-by-repeat homologous recombination rates. Prompted by our discovery of highly recombinogenic small repeats in P. abies, we assessed the genomic support for the prevailing hypothesis that intramolecular recombination is predominantly driven by repeat length, with larger repeats facilitating DNA exchange more readily. Overall, we found mixed support for this view: Recombination dynamics were heterogeneous across vascular plants and highly active small repeats (ca. 200 bp) were present in about one-third of studied mitogenomes. As in previous studies, we did not observe any robust relationships among commonly studied genome attributes, but we identify variation in recombination rates as a underinvestigated source of plant mitogenome diversity.

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  • 21.
    Sullivan, Alexis R.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Schiffthaler, Bastian
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Thompson, Stacey Lee
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Department of Biology, Dalhousie University, Halifax, NS, Canada.
    Street, Nathaniel R.
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Wang, Xiao-Ru
    Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC). Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Interspecific Plastome Recombination Reflects Ancient Reticulate Evolution in Picea (Pinaceae)2017In: Molecular biology and evolution, ISSN 0737-4038, E-ISSN 1537-1719, Vol. 34, no 7, p. 1689-1701Article in journal (Refereed)
    Abstract [en]

    Plastid sequences are a cornerstone in plant systematic studies and key aspects of their evolution, such as uniparental inheritance and absent recombination, are often treated as axioms. While exceptions to these assumptions can profoundly influence evolutionary inference, detecting them can require extensive sampling, abundant sequence data, and detailed testing. Using advancements in high-throughput sequencing, we analyzed the whole plastomes of 65 accessions of Picea, a genus of similar to 35 coniferous forest tree species, to test for deviations from canonical plastome evolution. Using complementary hypothesis and data-driven tests, we found evidence for chimeric plastomes generated by interspecific hybridization and recombination in the clade comprising Norway spruce (P. abies) and 10 other species. Support for interspecific recombination remained after controlling for sequence saturation, positive selection, and potential alignment artifacts. These results reconcile previous conflicting plastid-based phylogenies and strengthen the mounting evidence of reticulate evolution in Picea. Given the relatively high frequency of hybridization and biparental plastid inheritance in plants, we suggest interspecific plastome recombination may be more widespread than currently appreciated and could underlie reported cases of discordant plastid phylogenies.

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