SERTOLI CELLS IN TESTES CONTAINING OR LACKING GERM-CELLS - A COMPARATIVE-STUDY OF PARACRINE EFFECTS USING THE W-(C-KIT) GENE MUTANT MOUSE MODEL

Background: Paracrine effects of germ cells on Sertoli cell structure were examined in a mouse model with the W locus (dominant white spotti ng) mutation in which animals with the W/W-v genotype (referred to as mutants) lack virtually all germ cells. Results: Morphometric determin ation of Sertoli cell parameters in mutant and control (+/+) animals s howed that although the testes of mutant animals were about eight time s smaller than controls, the numbers of Sertoli cells in the two group s did not differ. Sertoli cell volume, Sertoli cell cytoplasmic and nu clear volumes, and Sertoli cell surface area in mutant animals were si gnificantly smaller than in control animals. Organelle volumes and sur face areas, expressed per cell, did not differ significantly in the tw o groups with one exception: the volume and surface area of smooth end oplasmic reticulum was significantly reduced in mutant animals. Plasma testosterone levels and tissue testosterone levels/testis were normal , indicating that the effects observed in the mutant animal were not s t consequence of androgen insufficiency. Plasma FSH was elevated, prob ably as a consequence of germ cell depletion, and was thought not to a ffect Sertoli cell parameters observed. Conclusions: The data suggest that paracrine interactions with germ cells do affect Sertoli cells by modifying the amount of smooth endoplasmic reticulum. These data focu s attention on the function of this abundant Sertoli cell organelle in promoting spermatogenesis. (C) 1994 Wiley-Liss, Inc.