Spermatogenesis and its fine structure of the seminiferous epithelium in the Jindo dog

진도견(珍島犬) 정세관상피(精細管上皮)의 정자발생(精子發生)과 미세구조(微細構造)

To investigate the cycle and relative frequences and the fine structure of seminiferous epithelia in mature Jindo dogs, histologic study was performed. The results obtained were summarized as follows; 1. Type A spermatogonia appeared approximately 1.6 times as many at stage II as compared to stage I while type In spermatogonia appeared small amount in stage III, IV and V. type B spermatogonia were found during the stage VI to VIII, though not detectable during stage I to V. The type B spermatogonia divided at stage VII to produce the preleptotene primary spermatocytes at stage VIII. The number of primary spermatocytes of the leptotene phase markedly increased during stage I to II, and the primary spermatocytes of the pachytene phase were shown the least in number at stage IV. The secondary spermatocytes could be seen only at stage IV. 2. The relative frequencies of each stage from stages I to VIII of the cycle of seminiferous epithelia were 31.6, 11.9, 10.0, 3.2, 8.2, 10.1, 11.7 and 13.2% respectively. 3. On electron microscopic observations, acrosomal vesicle of spermatids appeared larger though the bulk of germ cells were the morphologically same as those of the other animal species. Thread line structures light microscopically observed in the cytoplasm of Sertoli cell were the longitudinal orientation of mitochondria.