Control of final gonadal maturation in the hybrid sturgeon, bester.

每月检查成年雄性F1鲟鱼杂交种（最佳）（Huso huso L.雌性x Acipenser Acipenus L.雄性）的睾丸发育与血清性类固醇水平的关系。精子发生持续了1年，减数分裂一般从9月开始，精子发生在11月，虽然有相当大的变化，每月采样的鱼之间的睾丸发育阶段。在冬季，睾丸发育缓慢，一直持续到4月。鱼没有表现出自发精子，支持细胞的吞噬腔变得突出，从5月起。雄激素水平在精子发生过程中增加，并在整个精子形成前期保持较高水平。在退化阶段，11-酮睾酮浓度下降到低水平，B，而睾酮（T）水平仍然很高。在整个生殖周期中，17 α，20 β-二羟基-4-异戊烯-3-酮（DHP）的血清浓度较低。根据这些结果，建议 ...更多信息 本研究测定了培养的成年雌鱼血清雌二醇（E_2）T、DHP和卵黄蛋白原（VTG）水平的变化，并与卵巢发育的关系进行了分析。不同鱼类卵母细胞的发育差异很大。胚胎发育前期卵母细胞的发育一般伴随着第一批卵母细胞的退化。在卵黄发生个体中，卵巢由直径范围为0.6至2.6 mm的更高级的卵母细胞组成，并且在卵黄发生后的类中，卵母细胞在生殖泡向动物极迁移时达到其最大尺寸。具有迁移核的卵母细胞在冬季期间维持，并且在4月至5月开始大量退化，而没有生殖囊泡破裂（GVBD）或排卵发生。E2、T和VTG水平的季节性变化与卵子发生的进程密切相关。在卵黄发生期，E_2和VTG的水平分别从2-4 ng/ml和4-10 ng/ml下降到1-2 ng/ml和0.2-0.5 ng/ml，而T的水平仍然很高。相反，血清中的DHP水平在整个生殖周期中一直很低。这些结果表明，人工繁殖的适宜时间为卵母细胞发育后期的11月至4月。少

Testicular development in the adult male F1 sturgeon hybrid, the bester (Huso huso L.female x Acipenser ruthenus L.male) was examined monthly in relation to serum sex steroid levels. Spermatogenesis lasted for 1 year, with meiosis generally starting September and spermatogenesis in November, although there was considerable variation in testiculal developmental stages between fish sampled monthly. Testicular development continued, slowly, during the winter months until April. Fish did not exhibit spontaneous spermiation, and phagocytotic cavity of Sertoli cells became prominent from May onwards. Androgen levels increased during spermatogenesis and remained high throughout the pre-spermiation period. In the degeneration stage, 11-ketotestosterone concentrations declined to low levels, b while testosterone (T) levels remained high. The serum concentration of 17alpha, 20beta-dihydroxy-4-pregnen-3-one (DHP) was low throughout the reproductive cycle. Based on these resultss, it is suggested … More that the time appropriate for induction of final maturation would be from November-December to April when the testes are in the late stage of development.Changes in serum levels of estradiol-17beta (E_2)T,DHP and vitellogenin (VTG), in cultured adult female were examined in relation to ovarian development during a 1-year sampling period. Considerable variationsin oocyte development were found among fish. Oocytes at previtellogeenic ssatge generally started to develop conconitantly with the degeneration of the first batch ofoocyte. In vitellogenic individuals, ovaries were comprised of more advanced oocytes with diameter ranging from 0.6 to 2.6 mm and in the post-vitellogenic class, oocytes attained their largest size while the geminal vesicle was migrating towards the animal pole. Oocytes with a migrating nucleus were maintained during the winter period and massive degeneration started in April-May without germinal vesicle breakdown (GVBD) or ovulation occurring. Seasonal changes in E2, T and VTG levels were well correlated with the advancement of oogenesis. Their levels increased during vitellogenesis, whereas in the posstvitellogenic (migratory nucleus) stage the levels of E2 declined from 2-4 ng/ml to 1-2 ng/ml and VTG from 4-10 ng/ml to 0.2-0.5 ng/ml while T levels remained high. In contrast, serum levels of DHP were constantly low throughout the reproductive cycle. These results indicate that the time appropriate for induction of artificial reproduction would be from October-November to April-May when the oocytes are in the late stages of the development. Less