Unraveling the genotype by environment interaction in a thermosensitive fish with a polygenic sex determination system
Benjamin Geffroy, Mathieu Besson, Núria Sánchez-Baizán, Frédéric Clota, Alexander Goikoetxea, Bastien Sadoul, François Ruelle, Marie‐Odile Blanc, Hugues Parrinello, Sophie Hermet, Eva Blondeau‐Bidet, Marine Pratlong, Francesc Piferrer, Marc Vandeputte, François Allal
Abstract
Significance Traditionally, fish sex determination was considered to be governed by genetic or environmental factors. However, many teleost species defy this dichotomy. We combined genomic and transcriptomic approaches to characterize the temperature-dependent polygenic sex determination of European sea bass. We observed that the estimated genetic sex tendency (eGST) provides an accurate estimation of the phenotypic sex. Our data support the hypothesis that sexually dimorphic growth is the consequence rather than the cause of sex determination. We also showed that temperature-induced masculinization involves the up-regulation of sox3 and sox9a for individuals in the middle of the eGST distribution. We depict a sex determination system influenced by both continuous genetic and environmental variation that results in variable proportions of males and females.