OBJECTIVETo study the promoting effects of the epidermal growth factor (EGF) and stem cell factor (SCF) on the proliferation and differentiation of spermatogenic cells in mice.

METHODSWe cocultured in vitro spermatogenic cells of male mice aged 7 - 8 days in the medium with EGF and/or SCF at the concentrations of 5, 10, 20, 40 and 100 ng/ml, respectively. Then we observed the survival rate and morphological changes of the spermatogenic cells, detected the expressions of the pachytene-specific phosphoprotein gene (P19) and haploid sperm cell-specific transition protein gene (TP1), and analyzed the ploidy of the cells.

RESULTSAfter cocultured with EGF or SCF for 2 - 4 days, the spermatogenic cells began to proliferate in masses or chains in all concentration groups, most obviously in the 20 ng/ml EGF and 40 ng/ml SCF groups. At 7 days, both the number and survival rate of spermatogenic cells were significantly higher in the 20 ng/ml EGF and 40 ng/ml SCF groups than in the others (P < 0.05), and meanwhile, the P19/TP1 ratio was obviously decreased and the rate of haploid sperm markedly increased in the 40 ng/ml SCF group (P < 0.05). Combination of EGF and SCF remarkably promoted the proliferation of the spermatogenic cells (P < 0.05).

CONCLUSIONBoth EGF and SCF could increase the number and survival rate of spermatogenic cells. SCF could promote the formation of haploid sperm, and the combination of the two cytokines could enhance the effect on the proliferation of spermatogenic cells.