Data from: Neuroendocrine profiles associated with discrete behavioural variation in Symphodus ocellatus, a species with male alternative reproductive tactics

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.