title: Within-population Y-linked genetic variation for lifespan in Drosophila melanogaster.
abstract: The view that the Y chromosome is of little importance for phenotypic evolution stems from early studies of Drosophila melanogaster. This species' Y chromosome contains only 13 protein-coding genes, is almost entirely heterochromatic and is not necessary for male viability. Population genetic theory further suggests that non-neutral variation can only be maintained at the Y chromosome under special circumstances. Yet, recent studies suggest that the D. melanogaster Y chromosome trans-regulates hundreds to thousands of X and autosomal genes. This finding suggests that the Y chromosome may play a far more active role in adaptive evolution than has previously been assumed. To evaluate the potential for the Y chromosome to contribute to phenotypic evolution from standing genetic variation, we test for Y-linked variation in lifespan within a population of D. melanogaster. Assessing variation for lifespan provides a powerful test because lifespan (i) shows sexual dimorphism, which the Y is primarily predicted to contribute to, (ii) is influenced by many genes, which provides the Y with many potential regulatory targets and (iii) is sensitive to heterochromatin remodelling, a mechanism through which the Y chromosome is believed to regulate gene expression. Our results show a small but significant effect of the Y chromosome and thus suggest that the Y chromosome has the potential to respond to selection from standing genetic variation. Despite its small effect size, Y-linked variation may still be important, in particular when evolution of sexual dimorphism is genetically constrained elsewhere in the genome.
authors.affiliation: Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden.
authors.forename: R M
authors.initials: RM
authors.lastname: Griffin
authors.affiliation: Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden.|Department of Biology, Ecole Normale Supérieure de Cachan, Cachan, France.
authors.forename: D
authors.initials: D
authors.lastname: Le Gall
authors.affiliation: Department of Evolutionary Biology, Bielefeld University, Bielefeld, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Schielzeth
authors.affiliation: Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden.|IFM Biology, AVIAN Behavioural Genomics and Physiology Group, Linköping University, Linköping, Sweden.
authors.forename: U
authors.initials: U
authors.lastname: Friberg
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D004331:Drosophila melanogaster / Q000235:genetics* / Q000502:physiology*; D050173:Genes, Y-Linked / Q000502:physiology*; D014644:Genetic Variation; D008136:Longevity / Q000235:genetics*; D008297:Male
keywords: Y chromosome; intralocus sexual conflict; longevity; sex chromosomes; sexual dimorphism