中国大鲵生殖腺胚后发育的形态学观察

Morphological Study on the Postembryonic Development of the Gonad in the Chinese Giant Salamander Andrias davidianus

为探寻中国大鲵(Andrias davidianus)生殖腺胚后发育的特点及规律,采用解剖学与组织学技术对其形态结构变化进行了观察。结果表明,大鲵的原始生殖腺开始出现于出膜28～49 d;出膜133～175 d时一些个体生殖腺内已初步分化出原始卵泡;出膜259～343 d时一些个体生殖腺内已初步分化出生精小叶;出膜427 d时,卵巢已明显分化为皮质与髓质,且髓质内出现了卵巢腔,精巢内生精小叶及其内的腔隙、精巢间质等分化已较为明显;出膜511 d时精巢分化为明显的生精小叶和非成熟小叶两个区域。本文认为,大鲵与其他无羊膜类原始生殖腺的分化一般发生在胚后阶段,而且雌性的分化时间早于雄性。

In this study, the postembryonic development of the gonad in the Chinese Giant Salamander Andrias davidianus was observed using anatomical and histological techniques. The results showed that the original gonad appeared 28 -49 days after hatching, and primordial follicles which were composed of oocyte and somatic cells began to appear in some gonads 133 to 175 days after hatching. Seminiferous lobule differentiated in some gonads 259 - 343 days after hatching. On day 427 after hatching, the ovary was composed of cortex with more primordial follicles and medulla with ovarian cavity ; seminiferous lobules, cavity gap and testis interstitial tissue were present in the testis obviously. On day 511 after hatching, the testis was composed of seminiferous lobules and immature lobules. It was concluded that the post-embryonic differentiation of the original gonad in the Chinese Giant Salamander was similar to that of other anamniotes, and the gonad differentiation of the female oceured earlier than that of the male.