The role of Sertoli cells in the differentiation and exclusion of rat testicular germ cells in primary culture

We have previously established a primary co-culture of spermatogenic and somatic cells of the rat testis, in which spermatogenic cells differentiate to some extent in terms of the occurrence of testis-specific gene expression. In the present study, the interaction between spermatogenic and somatic Sertoli cells was investigated in this culture system. Spermatogenic differentiation did not proceed when these two cell types were placed on opposite sides of a permeable membrane, thus avoiding direct contact. Further, a significant proportion of spermatogenic cells died by apoptosis during culture, and Sertoli cells engulfed and digested the degenerating spermatogenic cells. These results indicate that Sertoli cells participate both in the differentiation of spermatogenic cells and in the exclusion of degenerating spermatogenic cells, by directly attaching to those cells.