A New Approach to Study the Architectural Arrangement of Spermatogenic Stages Revealed Little Evidence of a Partial Wave Along the Length of Human Seminiferous Tubules

Abstract

ABSTRACT: Although evidence of the spermatogenic wave in humans has been reported, little is known about the architectural arrangement of stages along the length of tubules in men with varied rates of sperm production. To conduct these studies, methodology is needed to stage relatively long lengths of straight portions of tubules in several men. Testes obtained at autopsy were glutaraldehyde perfused. Six men representing a range of daily sperm production were selected for this study. Wedges composed of groups of seminiferous tubules attached to the rete testis and separated by testicular septa were teased apart from the remaining testicular tissue, fixed in osmium, and oriented during Epon embedding. This orientation allowed for sections to be cut perpendicular to the length of the group of tubules, beginning at the end near where the tubules had been attached to the rete testis. Also, a tubule isolated away from the rete testis was oriented for perpendicular sectioning forone of the men. Several serial sections were cut at a setting of 22 μm, and each was optically sectioned approximately at 7 μm and photographed using Nomarski optics. Because many cytoplasmic and nuclear features of spermatogonia, spermatocytes, and spermatids were distinguished in photomicrographs produced by Nomarskl optics, this optical system facilitated the identification of stages of the spermatogenuc cycle in human seminiferous tubules. Hence, the three‐dimensional architectural arrangement of spermatogenic stages can be evaluatedand staged in thick, serial sections of straight, oriented human seminiferous tubules by optical sectioning and Nomarski optics. No evidence of a complete wave composed of all six stages was observed inany man, regardless of sperm production rate, even when the helical arrangement of stages was considered. When plotted in two dimensions, two to three tubular segments were composed of consecutive stages in an angular direction down the length of the tubule stages. Based on a new approach, there appeared to be a helical arrangement of subsequent stages in a partial wave, but no complete wave was observed in human seminiferous tubules. 1994 American Society of Andrology