EXPRESSION OF STEM-CELL FACTOR IN THE POSTNATAL RAT TESTIS

The expression of stem cell factor (SCF) mRNA and protein was examined in the postnatal rat testis. Northern blot analysis of total RNA from 1-4 days postpartum (dpp) testes showed none or barely detectable lev els of the similar to 6.5 kb SCF transcript. At 5 dpp, there was a str iking elevation in this mRNA, a timing that coincides with the onset o f spermatogonial proliferation, Immunohistochemical staining of testes showed that SCF protein was readily detected within Sertoli cells at 1-7 dpp and in the adult. Immunoreactive material was also detected wi thin gonocytes and within Leydig cells at 1-7 dpp and in Leydig cells in the adult. Given the intense staining of Leydig cells by two differ ent antibodies to SCF, the potential synthesis of SCF mRNA by these ce lls was investigated. Northern blot and reverse transcription/polymera se chain reaction analysis indicated that adult Leydig cells do not sy nthesize SCF mRNA, and Sertoli cells do. The significance of these fin dings is discussed in the context of germ cell-Sertoli cell interactio ns and Leydig cell function 1997. (C) 1997 Wiley-Liss, Inc.