IMMUNOLOCALIZATION OF ALBUMIN AND TRANSFERRIN IN GERM-CELLS AND SERTOLI CELLS DURING RAT GONADAL MORPHOGENESIS AND POSTNATAL-DEVELOPMENT OFTHE TESTIS

The localization of albumin and transferrin was examined immunohistoch emically in germ cells and Sertoli cells during rat gonadal morphogene sis and postnatal development of the testis. These proteins appeared a s early as the 13th day of gestation in migrating primordial germ cell s before Sertoli cell differentiation. In the fetal testis, strong imm unoreactivity was only detected in the gonocytes. In the prepubertal t estis, spermatogonia, primary spermatocytes, and some Sertoli cells ac cumulate albumin and transferrin. At puberty, different patterns of im munostaining of the germ cells were observed at the various stages of the cycle of the seminiferous epithelium. Diplotene spermatocytes at s tage XIII, spermatocytes in division at stage XIV, and round spermatid s at stages IV-VIII showed maximal staining. Labeling was evident in t he cytoplasm of adult Sertoli cells. Albumin and transferrin staining patterns paralleled each other during ontogenesis.