Transcriptome analyses and differential gene expression in a non-model fish species with alternative mating tactics

Area of Science:

• Behavioral Ecology
• Genomics
• Neurobiology

Background:

• Social dominance is crucial for male reproductive success in many species.
• In black-faced blennies (Tripterygion delaisi), males exhibit alternative mating strategies: territorial defense or sneaker reproduction.
• Understanding the molecular basis of these alternative strategies is key to explaining male dimorphism.

Purpose of the Study:

• To investigate the molecular signatures of male dimorphism in the black-faced blenny.
• To compare gene expression profiles between territorial males, sneaker males, and females.
• To identify novel genes associated with alternative mating strategies and social dominance.

Main Methods:

• RNA sequencing (RNAseq) was employed to profile gene expression in the brains of territorial males, sneaker males, and females.
• Differential gene expression analysis was conducted to identify genes with altered expression levels between the phenotypes.
• Comparative analysis was performed to assess the relative contributions of phenotypic plasticity and sexual dimorphism to gene expression patterns.

Main Results:

• More genes were differentially expressed between the two male phenotypes than between males and females.
• This suggests phenotypic plasticity plays a more significant role in gene expression during the reproductive period than sexual dimorphism.
• Territorial males overexpressed genes related to synaptic plasticity, while sneaker males overexpressed genes involved in differentiation and development.

Conclusions:

• Candidate genes for social dominance appear to be largely species-specific.
• This study presents a list of novel, differentially expressed genes in Tripterygion delaisi.
• This genome-wide study in a non-model species provides foundational molecular data for future research on social dominance and alternative mating strategies.