Relative positions of the spermatogenic stages in the mouse testis: morphological evidences for their non-randomized...

The topographical distribution pattern of the stages of the murine seminiferous epithelium cycle was investigated. PAS-hematoxylin stained testicular sections from adult mice representative of the apical, equatorial and caudal region of both testes, were used. The relative frequencies (RF) of the stages of the seminiferous epithelium cycle was estimated on the basis of more than 10,000 cross-sectioned seminiferous tubules identified according to the criteria of Leblond and Clermont (1952). It was found that in the testicular sections the stages of adjacent seminiferous tubules are not distributed randomly. The comparison of the RF of the stages (calculated over all the testicular sections) with the RF of the stages that are adjacent to a given seminiferous tubule stage suggests a clustered occurrence of numerically identical stages. These comparisons very often show statistically significant differences. The finding of such associations among adjacent segments of seminiferous tubules (stages) suggest the existence of an ordered distribution of the seminiferous tubules inside the testis possibly controlled by substances with local control capacity of spermatogenesis. On the basis of the findings here presented, it is suggested an interpretation of the phenomenon of modulations of the waves of the seminiferous epithelium.