Hormonal regulation of spermatid binding.
A Sertoli-spermatid coculture model is described in which a large percentage (greater than 76%) of round spermatids remain viable for 48 h and bind to Sertoli cells. The effects of follicle-stimulating hormone (FSH) and testosterone on spermatid binding (expressed as the spermatid density; SD = the number of spermatids per unit area of Sertoli cell cytoplasm), ultrastructure of the Sertoli-spermatid junctional complex, and distribution in the Sertoli cell of junction-related F-actin and vinculin are described. Following 48 h of incubation, neither FSH alone nor testosterone alone affected spermatid binding to Sertoli cells beyond that observed in control cocultures. However, the combination of FSH and testosterone (FSH + testosterone) resulted in a significant increase in the density of spermatids bound to Sertoli cells. Junction-related structure of the Sertoli cell cytoskeleton between the Sertoli cell and the pre-step 8 spermatid was different than that observed between the Sertoli cell and the post-step 8 spermatid. The junction-related cytoskeletal modification of the Sertoli cell (JCMS) in the latter was similar in appearance to the well-described 'Sertoli ectoplasmic specialization' observed adjacent to post-step 8 spermatids in vivo. FSH + testosterone and FSH alone, but not testosterone alone, resulted in the peripheral distribution of actin and vinculin, which otherwise remained in stress fiber-like structures throughout the Sertoli cell. Results show that maximal spermatid binding to Sertoli cells in vitro requires FSH + testosterone and is associated with the peripheral distribution of actin and vinculin.
Cameron
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DF
Department of Anatomy, University of South Florida College of Medicine, Tampa 33612.
Muffly
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KE
D000199:Actins / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D003599:Cytoskeleton / Q000187:drug effects / Q000648:ultrastructure; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D066298:In Vitro Techniques; D007365:Intercellular Junctions / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D051381:Rats; D011919:Rats, Inbred Strains; D012708:Sertoli Cells / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D013087:Spermatids / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D013739:Testosterone / Q000494:pharmacology*; D016596:Vinculin / Q000378:metabolism
D000199:Actins; D016596:Vinculin; D013739:Testosterone; D005640:Follicle Stimulating Hormone