Function of stem cell factor (SCF) as a survival factor of spermatogonia and localization of messenger ribonucleic acid in the rat seminiferous epithelium
Hakovirta,Harri; Yan,Wei; Kaleva,Marko; Zhang,Fuping; Vantinnen,Kateriina; Morris,Patricia L.; Soder,Molle; Parvinen,Martti; Toppari,Jorma
Endocrinology 140(3): 1492-1498
Publication date: 1999
To address the possibility that stem cell factor (SCF) is aparacrine regulator of germ cell development in the adult rattestis, stage-specific distribution of SCF messenger RNA (mRNA)was investigated with Northern blot and in situ hybridizationanalyses. The highest levels of SCF mRNA were found in stagesII-VI of the rat seminiferous epithelial cycle, whereasthe lowest levels were in stages VII-VIII. Intermediatelevels of SCF mRNA were detected in stages IX-XIV-Iof the cycle. The expression of the SCF gene was found to bedevelopmentally regulated, and the expression pattern followedthe process of Sertoli cell proliferation and differentiationduring postnatal life. The effect of mouse recombinant SCF onspermatogonial DNA synthesis was studied using an in vitro tissueculture system for stage-defined seminiferous tubules. A significantincrease in DNA synthesis in spermatogonia could be detectedwhen tubule segments from stage XII were cultured in the presenceof 100 ng/ml SCF for 48 h (P < 0.05) and 72 h (P < 0.01).This observation was further confirmed with autoradiographic analyses;almost a 100-fold increase in thymidine incorporation in the SCF-treated(100 ng/ml) tubule segments was observed compared with that inuntreated samples. The results of the present study suggestthat SCF is a Sertoli cell-produced paracrine regulator andacts as a survival factor for spermatogonia in the adult ratseminiferous epithelium in a stage-specific manner.