Steroids and gonadal sex differentiation in the rainbow trout, Oncorhynchus mykiss
Guiguen, Y.; Govoroun, M.; Cotta, H.D.; McMeel, O.M.; Fostier, A. (2000). Steroids and gonadal sex differentiation in the rainbow trout, Oncorhynchus mykiss, in: Norberg, B. et al. (Ed.) Proceedings of the 6th International Symposium on the Reproductive Physiology of Fish, Bergen, Norway, July 4-9, 1999. pp. 241-243
In: Norberg, B. et al. (2000). Proceedings of the 6th International Symposium on the Reproductive Physiology of Fish, Bergen, Norway, July 4-9, 1999. International Symposium on the Reproductive Physiology of Fish, 6. Department of Fisheries and Marine Biology, University of Bergen: Bergen. ISBN 82-7461-048-2. 499 pp., more
In: International Symposium on the Reproductive Physiology of Fish. Museo Nacional de Ciencias Naturales. , more
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| Authors | | Top |
- Guiguen, Y.
- Govoroun, M.
- Cotta, H.D.
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| Abstract |
Steroidogenic potentialities and steroid receptivity of rainbow trout gonads were investigated in relation to sexual differentiation by using in vivo experimental treatments, in vitro metabolism analysis and the characterization of steroid enzymes (aromatase P450ar, 11 beta -hydroxylase P450c11) and steroid receptors (androgen AR alpha and AR beta , estrogen ER) gene expressions. Estrogens or 11-oxygenated androgens were specifically synthesized during ovarian and testicular differentiation respectively. In vivo treatments with 11 beta -hydroxyandrostenedione (11 beta Delta 4) or ATD, an aromatase inhibitor, induced a complete masculinization, but treatment with metopyrone, a specific inhibitor of P450c11, had no effect. In vivo treatments with steroid receptors antagonists also had no effect. P450ar and P450c11 gene expressions were specifically detected during ovarian differentiation and during testicular differentiation, respectively. Expression of AR alpha , AR beta and ER were detected at a very early stage but did not show any clear sex specific pattern. Taken all together, these results demonstrate that steroids are physiologically involved in fish gonadal differentiation, and that steroid enzyme potentialities are key steps in that process. |
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