title: Neuroendocrine profiles associated with discrete behavioural variation in Symphodus ocellatus, a species with male alternative reproductive tactics.
abstract: The molecular mechanisms underlying phenotypic plasticity are not well understood. Identifying mechanisms underlying alternative reproductive tactics (ARTs) in species for which the behavioural and fitness consequences of this variation are well characterized provides an opportunity to integrate evolutionary and mechanistic understanding of the maintenance of variation within populations. In the ocellated wrasse Symphodus ocellatus, the behavioural phenotypes of three distinct male morphs (sneakers, satellites and nesting males), which arise from a single genome, have been thoroughly characterized. To determine the neuroendocrine and genomic mechanisms associated with discrete phenotypic variation and ARTs in S. ocellatus in their natural environment, we constructed a whole-brain de novo transcriptome and compared global patterns of gene expression between sexes and male morphs. Next, we quantified circulating cortisol and 11-ketotestosterone (11-kt), mediators of male reproductive behaviours, as well as stress and gonadal steroid hormone receptor expression in the preoptic area, ventral subpallial division of the telencephalon and dorsolateral telencephalon, critical brain regions for social and reproductive behaviours. We found higher levels of 11-kt in nesting males and higher levels of cortisol in sneaker males relative to other male morphs and females. We also identified distinct patterns of brain region-specific hormone receptor expression between males such that most hormone receptors are more highly expressed in satellites and nesting males relative to sneakers and females. Our results establish the neuroendocrine and molecular mechanisms that underlie ARTs in the wild and provide a foundation for experimentally testing hypotheses about the relationship between neuromolecular processes and reproductive success.
authors: Department of Ecology and Evolutionary Biology, Yale University, 165 Prospect St., New Haven, CT, 06520, USA. bnugent@vet.upenn.edu.|Department of Integrative Biology, Center for Computational Biology and Bioinformatics, The University of Texas at Austin, 2415 Speedway, Austin, TX, 78712, USA. bnugent@vet.upenn.edu.
authors: B M
authors: BM
authors: Nugent
authors: Department of Ecology and Evolutionary Biology, Yale University, 165 Prospect St., New Haven, CT, 06520, USA.|Department of Psychology, Southern Connecticut State University, 501 Crescent St., New Haven, CT, 06515, USA.
authors: K A
authors: KA
authors: Stiver
authors: Department of Ecology and Evolutionary Biology, Yale University, 165 Prospect St., New Haven, CT, 06520, USA.|Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, 1156 High St., Santa Cruz, CA, 95064, USA.
authors: S H
authors: SH
authors: Alonzo
authors: Department of Integrative Biology, Center for Computational Biology and Bioinformatics, The University of Texas at Austin, 2415 Speedway, Austin, TX, 78712, USA.
authors: H A
authors: HA
authors: Hofmann
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D005260:Female; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D009425:Nesting Behavior; D009490:Neurosecretory Systems / Q000502:physiology*; D010473:Perciformes / Q000235:genetics / Q000502:physiology*; D010641:Phenotype; D012098:Reproduction; D012726:Sexual Behavior, Animal; D013739:Testosterone / Q000031:analogs & derivatives / Q000097:blood; D059467:Transcriptome
chemical_list: D013739:Testosterone; C003600:11-ketotestosterone; D006854:Hydrocortisone
keywords: alternative reproductive tactics; brain; gene expression; hormones