A Unique Cytoplasmic Marker for Extratesticular Sertoli Cells

In the absence of a definitive cell marker for testis-derived Sertoli cells, their identification in cell culture or in Sertoli cell-facilitated cell transplantation protocols is difficult and limits the creditable evaluation of experimental results. However, the production by prepubertal Sertoli cells of Mullerian inhibiting substance (MIS) presents the possibility of specifically identifying extratesticular Sertoli cells as well as Sertoli cells in situ, by the immunodection of this unique glycoprotein. This study was designed to determine if isolated rat Sertoli cells could be identified by routine immunocytochemistry utilizing an antibody raised against MIS. Sertoli cells immunostained for MIS included Sertoli cells in situ and freshly isolated, cultured and cocultured Sertoli cells, and Sertoli cells structurally integrated with NT2 cells in simulated microgravity. Detection of MIS was also determined by Western blot analysis.