The follicular sensitivity in vitro to maturation-inducing hormones in rainbow trout, Salmo gairdneri: Role of oestradiol-17β

Bernard Jalabert (1) , Alexis Fostier (1)

1 Laboratoire de physiologie des poissons

Trout ovaries were processed in vitro to determine relationships between the following parameters — oocyte sensitivity to the maturational steroid 17α-hydroxy-20β-dihydroprogesterone (17α,20β-OH-P); follicular sensitivity to the maturational gonadotropin s-GtH; inhibitory potency of exogenous oestradiol-17β (E2) during s-GtH-induced maturation; and level of E2 in the plasma. The sensitivity to hormones was estimated by the median efficient dose (MED) for oocyte maturation in vitro. The peripheral migration of the germinal vesicle coincided with an increase in oocyte sensitivity to 17α,20β-OH-P. A significant correlation was observed between plasma E2 level and the follicular sensitivity to s-GtH, but not between plasma E2 and the oocyte sensitivity to 17α,20β-OH-P. It was concluded that the peripheral migration of the GV is a morphological event which coincides with an increase in oocyte sensitivity, and that E2 is a physiological regulator of follicular sensitivity to GtH.

Mots clés: fish; rainbow trout; oocyte maturation; salmonids; trout; rainbow

Mots clés: poisson; salmonidae; truite arc en ciel; oncorhynchus mykiss; salmo gairdneri; estradiol 17beta; gth; reproduction; maturation ovocytaire

Domaines: Sciences du Vivant [q-bio]

Bernard Jalabert, Alexis Fostier. The follicular sensitivity in vitro to maturation-inducing hormones in rainbow trout, Salmo gairdneri: Role of oestradiol-17β. Aquaculture, 1984, 43 (1-3), pp.1-11. ⟨10.1016/0044-8486(84)90004-8⟩. ⟨hal-01601161⟩