Evidence of a wave of spermatogenesis in human testis.

The present report documents the strikingly regular appearance and arrangement of the spermatogenic stages i seminiferous tubules of two aged males. Analysis of the pattern of distribution of the stages in seminiferous tubules of two aged males. Analysis of the pattern of distribution of the stages in two-dimensional maps of the seminiferous tubules revealed the presence of helically arranged sequences of stages. Similar results were obtained from testicular tissue of a younger patient. The present findings indicate the existence of a spermatogenic wave in human seminiferous tubules. It is suggested that the particular pattern of the human seminiferous epithelium may emerge from a specific mode of spermatogonial proliferation and renewal.