RNA synthetic activities of sertoli cells in the mouse testis.

Abstract

Electron microscope autoradiographic studies of RNA synthesis in Sertoli cells of the adult mouse, using [‘H]uridine as a precursor, show a random distribution of grains in the nucleoplasmic area and a localized product on the nucleolar fibrillar component at early labeling times (15 mm). The condensed chromatin bodies associated with the nucleolus seem to have a nucleolar organizing function. At later labeling times (3 h) certain interchromatmn granules occurring in clusters in the nucleoplasm become partially labeled. After 7-8 days, the disappearance of label from Sertoli cells, contrasting with the longer persistence in spermatocytes, suggests a rapid turnover of RNA in Sertoli cells. Differential labeling patterns and structural changes in Sertoli cells cytoplasm are related to variations in functional activities presumably required for normal spermatogenesis and/or spermiogenesis. Sertoli cells are found in the seminiferous epithelium of several mammalian species. Though various functions have been attributed to these cells, it is generally accepted that Sertoli cells provide mechanical support for germinal cells. Moreover, they participate in the release of sperm into the lumen of the seminiferous tubules (VitaleCalpe and Burgos, 1970), dispose of cell debris by a phagocytic mechanism (Clegg and Macmillan, 1965; Kierszenbaum, 1970), and play an important role in the transfer of nutrients and metabolites between the intertubular space and the lumen of the tubules, acting as “bridge” cells (Vilar et al., 1962). It is also known that Sertoli cells constitute a unique stable cell population in the seminiferous epithelium. Whereas spermatogonia, spermatocytes, and sper