title: Sperm competition shapes gene expression and sequence evolution in the ocellated wrasse.
abstract: Gene expression differences between males and females often underlie sexually dimorphic phenotypes, and the expression levels of genes that are differentially expressed between the sexes are thought to respond to sexual selection. Most studies on the transcriptomic response to sexual selection treat sexual selection as a single force, but postmating sexual selection in particular is expected to specifically target gonadal tissue. The three male morphs of the ocellated wrasse (Symphodus ocellatus) make it possible to test the role of postmating sexual selection in shaping the gonadal transcriptome. Nesting males hold territories and have the highest reproductive success, yet we detected feminization of their gonadal gene expression compared to satellite males. Satellite males are less brightly coloured and experience more intense sperm competition than nesting males. In line with postmating sexual selection affecting gonadal gene expression, we detected a more masculinized expression profile in satellites. Sneakers are the lowest quality males and showed both de-masculinization and de-feminization of gene expression. We also detected higher rates of gene sequence evolution of male-biased genes compared to unbiased genes, which could at least in part be explained by positive selection. Together, these results reveal the potential for postmating sexual selection to drive higher rates of gene sequence evolution and shape the gonadal transcriptome profile.
authors.affiliation: Department of Genetics, Evolution and Environment, University College London, London, UK.|School of Biological Sciences, Monash University, Clayton, VIC, Australia.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Dean
authors.affiliation: Department of Genetics, Evolution and Environment, University College London, London, UK.
authors.forename: Alison E
authors.initials: AE
authors.lastname: Wright
authors.affiliation: Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA.|Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Marsh-Rollo
authors.affiliation: Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA.|Department of Biomedical Sciences, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Bridget M
authors.initials: BM
authors.lastname: Nugent
authors.affiliation: Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA.|Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, USA.
authors.forename: Suzanne H
authors.initials: SH
authors.lastname: Alonzo
authors.affiliation: Department of Genetics, Evolution and Environment, University College London, London, UK.
authors.forename: Judith E
authors.initials: JE
authors.lastname: Mank
mesh_terms: D000818:Animals; D019143:Evolution, Molecular; D005260:Female; D008297:Male; D010473:Perciformes / Q000235:genetics*; D010641:Phenotype; D012098:Reproduction; D012726:Sexual Behavior, Animal; D013094:Spermatozoa / Q000502:physiology*; D059467:Transcriptome
keywords: alternative reproductive tactics; expression variance; masculinization; morphs; positive selection; sex-biased genes