Effects of growth-promoting factors on proliferation of mouse spermatogonial stem cells (SSCs) in vitro
The proliferation, cultivation and identification of spermatogonial stem cells (SSCs) in vitro are critical to our understanding of male infertility, genetic resources and endangered species conservation. To investigate the effects of growth-promoting factors, epidermal growth factor (EGF), insulin-like growth factor-1 (IGF-1) and basic fibroblast growth factor (bFGF) on the proliferation of mouse (SSCs) in vitro, three culture schemes (single factor, double factor combinations and triple factor combinations) were designed to culture mouse SSCs in vitro. The optimal proliferation rate of SSCs cultivation in vitro among single factor groups, double factor combinations and triple factor combinations was 41.60, 61.00 and 56.60%, respectively. The results of the proliferation rates of SSCs cultivation in vitro indicated that 10 ng/ml EGF based on pre-treatment with 30 ng/ml 10% follicle stimulating hormone (FSH) was able to greatly enhance the proliferation of mouse SSCs in vitro. The 20 ng/ml EGF and 20 ng/ml IGF-1 combination based on post-treatment with 30 ng/ml 10% FSH, and the 20 ng/ml EGF, 20 ng/ml IGF-1 and 10 ng/ml bFGF combination based on post-treatment with 30 ng/ml 10% FSH were a preferable combination to the proliferation of SSCs cultivation, respectively. In conclusion, it was apparent that 20 ng/ml EGF and 20 ng/ml IGF-1 was the optimal combination which could stimulate the proliferation of mouse SSCs in vitro.
Key words: Growth-promoting factors, mouse spermatogonial stem cells (SSCs), proliferation.