中国大鲵闭锁卵泡的显微和超微结构观察

摘要

The microstructure and ultrastructure of the atretic follicle and corpora atretica in the ovary of Chinese giant salamander Andrias davidianus were observed with light and electron microscopy. The results showed that corpora atretica arise from follicular cells and thecal cells do not invade the oocytes. During the slow growth stage of the ovum, few atretic follicles can be found. In May and June, when most oocytes in the ovary have entered into the previtellogenic stage,atretic follicles were observed, but the steroidogenic features of these cells were not striking. In July and August, when most oocytes were in vitellogenic stage, there were some mitochondria with tubular eristae, plenty of smooth endoplasmic reticulum and lipid droplets, and a well-developed Golgi complex in the corpora atretie cells. These cytological features displayed that the corpora atretica may secrete steroid hormones and regulate normal ovum maturation. We propose that these structures be termed as preovulatory corpora lutea in this species [Acta Zoologica Sinica 50 (4): 615 -621, 2004].%用光镜和电镜观察了中国大鲵卵泡闭锁过程和闭锁小体的显微和超微结构.结果显示,大鲵闭锁小体是卵泡细胞侵噬卵母细胞并增殖形成细胞团,膜细胞未参与.在大部分卵泡处于缓慢生长期时,未发现卵泡闭锁现象;在5、6月份,卵巢内大部分卵母细胞进入卵黄形成前期,部分卵泡闭锁,但闭锁小体细胞的类固醇激素分泌结构特征不明显;在7、8月份,大多数卵母细胞处于卵黄形成期,闭锁小体细胞具有管泡状嵴线粒体、丰富的滑面内质网和脂滴、发达的高尔基体等.这些细胞学特征表明闭锁小体可分泌类固醇激素,以调节正常卵子的成熟.在大鲵中观察到的闭锁小体属于排卵前黄体[动物学报50(4):615-621,2004].