Characterization of Sertoli cell‐germ cell junctional specializations in dissociated testicular cells

Abstract

To further characterize Sertoli cell-germ cell junctional specializations seminiferous tubules from sexually mature Sprague-Dawley rats were dissociated by enzymatic and mechanical methods. Ultrastructural analysis of cell suspensions prepared by incubation in collagenase alone or by mechanical methods revealed that spermatids remained attached to Sertoli cells or Sertoli cell fragments. Such cellular associations were found only between Sertoli cell fragments and spematids in which the developing acrosome had made contact with the plasma membrane (step 8 and subsequent steps of spermiogenesis). Furthermore, the fragments were confined to that region of the plasma membrane over the acrosome. The Sertoli cell half of this adhesive site displayed the typical elements of Sertoli cell junctions, filamentous bundles and associated cisterna of endoplasmic reticulum, in apposition to the spermatids. The spermatids demonstrated no surface specializations at the attachment sites. In contrast, in cell suspensions prepared with trypsin, spermatids were free of attachments to Sertoli cells or their fragments. These results demonstrate that: (1) the junctions act to bind cells together, (2) adhesive type contact is established between Sertoli cells and spermatids at step 8 and subsequent steps of spermiogenesis, (3) contact is restricted to the spermatid plasma membrane over the acrosome, and (4) spermatids can be freed from the junctional specializations by treatment with trypsin.

A complex containing α6β1-integrin and phosphorylated focal adhesion kinase between Sertoli cells and elongated spermatids during spermatid release from the seminiferous epithelium

“…These structures are thought to participate in spermatid head shaping, adhesion of the spermatid to the Sertoli cell during spermiation and the removal of ES junctions (Romrell & Ross 1979, Tanii et al 1999, Guttman et al 2002. The immunostaining of proteins involved in TBCs is clearly localised to Sertoli cell cytoplasm in the inner ventral curvature of the spermatid head during spermiation (Guttman et al 2004), as TBCs predominantly arise in this area (Russell 1993).…”

Identification of Specific Sites of Hormonal Regulation in Spermatogenesis in Rats, Monkeys, and Man

“…Linkages between Sertoli cells and the spermatid acrosome have been observed by electron microscopy (Russell et al, 1988), which presumably contribute to a strong adhesive domain as mechanical disruption of the seminiferous epithelium results in spermatids with attached fragments of Sertoli cell cytoplasm containing ES (Romrell and Ross, 1979). One candidate CAM is ␣6␤1-integrin, which has been immunolocalised to the junction between Sertoli cells and both round and elongating spermatids (Palombi et al, 1992;Salanova et al, 1995;Mulholland et al, 2001) and may be involved in a signaling complex with integrin-linked kinase (Mulholland et al, 2001).…”

Do Nonspermatozoal Cells Mainly Stem from Spermiogenesis? Study of 106 Fertile and 102 Subfertile Men

“…However, altered spermatogonia and spermatocytes are often phagocytosed by Sertoli cells [24] or in the epididymis [171 instead of being liberated in the seminal fluid as spermatids. If phagocytosis involved a great number of cells, our conclusion would no longer be adequate.…”