THE ROLE OF SERTOLI CELLS IN THE DIFFERENTIATION AND EXCLUSION OF RATTESTICULAR GERM-CELLS IN PRIMARY CULTURE

We have previously established a primary coculture of spermatogenic an d somatic cells of the rat testis, in which spermatogenic cells differ entiate to some extent in terms of the occurrence of testis-specific g ene expression. ln the present study, the interaction between spermato genic and somatic Sertoli cells was investigated in this culture syste m. Spermatogenic differentiation did not proceed when these two cell t ypes were placed on opposite sides of a permeable membrane, thus avoid ing direct contact. Further, a significant proportion of spermatogenic cells died by apoptosis during culture, and Sertoli cells engulfed an d digested the degenerating spermatogenic cells. These results indicat e that Sertoli cells participate both in the differentiation of sperma togenic cells and in the exclusion of degenerating spermatogenic cells , by directly attaching to those cells.