抄録
Histology of the seminiferous epithelium of the rat testis is described at the light microscope level. The morphologies of male germ cells (spermatogonia, spermatocytes, and spermatids) undergoing the spermatogenesis are depicted chronologically using PAS-stained materials, and correlated with 14 stages of the seminiferous epithelium, 11 phases of diploid germ cells, and 19 steps of transformation of haploid germ cells. Developmental sequence of the spermatogenesis at any portions of the seminiferous tubules occurs continuously but at a certain moment the germ cell types observed in situ are distinctive in morphology and limited in number. Each facet of the epithelium displays several time-sliced windows of the continuous spermatogenetic sequence. The assembly patterns of male germ cell types characterize the stages of the epithelium (stage I to XIV), which are determined primarily by cellular and subcellular transformations of spermatids. Since the spermiogenesis of spermatids is comprised of 19 steps according to the acrosomal development, the remaining steps are overlaid in the cycle of stages. Thus, the two different, successive generations of spermatids are compiled in the same facets of the epithelium, in particular in stage I to VIII. The same applies to spermatocytes, different phases of which are stratified deep in the epithelium. The correlation between the chronological sequence of the spermatogenesis and the pictorial presentation of male germ cells can provide a clue for understanding the stratified cellular components in the epithelium, and will help identify and describe the male germ cell types properly for diverse arrays of analyses in advanced studies.
