Environmental effects on fish sex determination and differentiation

Baroiller Jean-François, D'Cotta Helena, Saillant E.. 2009. Environmental effects on fish sex determination and differentiation. Sexual Development, 3 : 118-135.

Quartile : Q2, Sujet : DEVELOPMENTAL BIOLOGY

Résumé : Environmental factors affect the sex ratio of many gonochoristic fish species. They can either determine sex or influence sex differentiation. Temperature is the most common environmental cue affecting sex but density, pH and hypoxia have also been shown to influence the sex ratio of fish species from very divergent orders. Differential growth or developmental rate is suggested to influence sex differentiation in sea bass. Studies in most fish species used domestic strains reared under controlled conditions. In tilapia and sea bass, domestic stocks and field-collected populations showed similar patterns of thermosensitivity under controlled conditions. Genetic variability of thermosensitivity is seen between populations but also between families within the same population. Furthermore, in the Nile tilapia progeny testing of wild male breeders has strongly suggested the existence of XX males in 2 different natural populations. Tilapia and Atlantic silverside studies have shown that temperature sensitivity is a heritable trait which can respond to directional (tilapia) or frequency dependent selection. In tilapia, transitional forms within a genetic sex determination (GSD) and environmental sex determination (ESD) continuum seem to exist. Temperature regulates the expression of the ovarianaromatase cyp19a1 which is consistently inhibited in temperature masculinized gonads. Foxl2 is suppressed before cyp19a1. Recent in vitro studies have shown that foxl2 activates cyp19a1, suggesting that temperature acts directly on foxl2 or further upstream. Dmrt1 up-regulation is correlated with temperature-induced male phenotypes. Temperature through apoptosis or germ cell proliferation could be a critical threshold for male or female sex differentiation.

Mots-clés Agrovoc : poisson (animal), Oreochromis niloticus, facteur du milieu, détermination du sexe, différenciation sexuelle, tilapia (genre), Dicentrarchus labrax

Classification Agris : L53 - Physiologie animale - Reproduction
M11 - Production de la pêche

Champ stratégique Cirad : Axe 1 (2005-2013) - Intensification écologique

Auteurs et affiliations

• Baroiller Jean-François, CIRAD-PERSYST-UPR Aquaculture (FRA) ORCID: 0000-0002-0992-1725
• D'Cotta Helena, CIRAD-PERSYST-UPR Aquaculture (FRA) ORCID: 0000-0003-2739-3476
• Saillant E., University of Southern Mississippi (USA)

Source : Cirad - Agritrop (https://agritrop.cirad.fr/550714/)

Métriques

[ Page générée et mise en cache le 2024-12-22 ]