Agritrop
Accueil

Search for genes involved in the temperature-induced gonadal sex differentiation in the tilapia, Oreochromis niloticus

D'Cotta Helena, Fostier Alexis, Guiguen Yann, Govoroun Marina, Baroiller Jean-François. 2001. Search for genes involved in the temperature-induced gonadal sex differentiation in the tilapia, Oreochromis niloticus. Journal of Experimental Zoology, 290 (6) : 574-585.

Article de revue ; Article de revue à facteur d'impact
[img] Version publiée - Anglais
Accès réservé aux personnels Cirad
Utilisation soumise à autorisation de l'auteur ou du Cirad.
document_484851.pdf

Télécharger (588kB)

Type d'url non précisé : http://onlinelibrary.wiley.com/doi/10.1002/jez.1108/pdf

Résumé : In the tilapia, Oreochromis niloticus, sexis determined by genetic factors (XX/XY) but temperature can also influence the gonadal sex differentiation. Elevated temperatures of 35°C can generate functional male phenotypes if applied before and during sexual differentiation. The genes and mechanisms by which temperature acts on the cascade leading to sex differentiation have been investigated. Two strategies have been followed: 1) Search for novel genes by differential display, and 2) Expression studies of candidate genes. Genetically all-female and all-male progenies were reared at 27°C (natural temperature) and at 35°C (masculinizing treatment) and gonads dissected. Using differential display, we isolated a 300 bp cDNA (MM20C) from temperature-masculinized females.Virtual norther nanalysis revealed a 1.2 kb transcriptin 35°C treated females and males, but hardly any expression in natural females (27°C). Semi-quantitative RT-PCR established a several-fold increase in MM20C expression in 35°C masculinized fry. Elevated expression was observed in natural males (27°C) with higher levels detected in those reared at 35°C. Furthermore, we have analyzed as a candidate gene the P450 11 bêta-hydroxylase, an important androgen steroidogenic enzyme. Low levels of expression were found in natural males. This coincides with low concentrations of 11 ketotestosterone in the gonads before and during gonadaI sex differentiation. Higher expression levels of 11 bêta-hydroxylase were detected in male gonads at 35°C but levels in phenotypic males were similar to those found for natural females. Previous results reported that expression of a romataseis repressed by masculinizing treatments. Our study demonstrated that masculinizing-temperature can also stimulate the expression of other gene(s).

Classification Agris : L52 - Physiologie animale - Croissance et développement

Auteurs et affiliations

Autres liens de la publication

Source : Cirad - Agritrop (https://agritrop.cirad.fr/484851/)

Voir la notice (accès réservé à Agritrop) Voir la notice (accès réservé à Agritrop)

[ Page générée et mise en cache le 2024-03-20 ]