Spermiogenosis and fine structure of the sertoli cell junctional specialization in the Jindo dog I. Studies on spermiogenesis in the Jindo dog

진도견(珍島犬)의 정자형성(精子形成)과 Sertoli세포(細胞) 특수(特殊) 연접부(連接部)의 미세구조(微細構造) I. 진도견(珍島犬)의 정자형성(精子形成)에 관한 연구(硏究)

Classification of the cycle of seminiferous epithelia into 12 stages by the morphological changes in acrosomal system and evaluation of the relative frequency of stages and the cell association were histologically performed in the mature Korean native Jin-do dogs. The results were summarized as follows; 1. The minimum number of type A spermatogonia averaged 1.01 at stages I, while maximum number averaged 2.47 at stages XII. Some type A spermatogonia divided at stage XII to produce the type intermediate(IN) spermatogonia at the following stage I. The type IN spermatogonia divided at stage IV to produce the type B spermatogonia at stage V. 2. The type B spermatogonia divided at stage VI to produce the preleptotene primary spermatocytes at stage VII. The secondary spermatocytes observed at stage XII. The secondary spermatocytes observed at stage XII divided to give rise to the round spermatids at the following stage I. The numbers of the first spermatocytes and spermatids were almost constant, respectively, through all the cycles of seminiferous epithelium. 3. The acrosomal vesicle was invaginated to occupy one third to half of spermatid nucleus at the cap phase, which was different from that of rodent and ruminant spermatid nuclei. 4. The relative frequencies of stages I to XII of seminiferous epithelia cycle were 10.34, 4.84, 5.03, 8.22, 10.86, 6.63, 6.42, 18.88, 10.17, 6.18, 7.62% and 4.81%, respectively.