Evolution of haploid selection in predominantly diploid organisms
2015 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 112, no 52, 15952-15957 p.Article in journal (Refereed) PublishedText
Diploid organisms manipulate the extent to which their haploid gametes experience selection. Animals typically produce sperm with a diploid complement of most proteins and RNA, limiting selection on the haploid genotype. Plants, however, exhibit extensive expression in pollen, with actively transcribed haploid genomes. Here we analyze models that track the evolution of genes that modify the strength of haploid selection to predict when evolution intensifies and when it dampens the "selective arena" within which male gametes compete for fertilization. Considering deleterious mutations, evolution leads diploid mothers to strengthen selection among haploid sperm/pollen, because this reduces the mutation load inherited by their diploid offspring. If, however, selection acts in opposite directions in haploids and diploids ("ploidally antagonistic selection"), mothers evolve to reduce haploid selection to avoid selectively amplifying alleles harmful to their offspring. Consequently, with maternal control, selection in the haploid phase either is maximized or reaches an intermediate state, depending on the deleterious mutation rate relative to the extent of ploidally antagonistic selection. By contrast, evolution generally leads diploid fathers to mask mutations in their gametes to the maximum extent possible, whenever masking (e.g., through transcript sharing) increases the average fitness of a father's gametes. We discuss the implications of this maternal-paternal conflict over the extent of haploid selection and describe empirical studies needed to refine our understanding of haploid selection among seemingly diploid organisms.
Place, publisher, year, edition, pages
2015. Vol. 112, no 52, 15952-15957 p.
pollen competition, antagonistic selection, haploid selection, sperm competition, evolutionary theory
IdentifiersURN: urn:nbn:se:uu:diva-274434DOI: 10.1073/pnas.1512004112ISI: 000367234700061PubMedID: 26669442OAI: oai:DiVA.org:uu-274434DiVA: diva2:896514
FunderSwedish Research Council, VR 621-2010-5670EU, European Research Council, 336633-HapSelA