Overexpression of the GDNF gene in buffalo Sertoli cells. After 15 days of transfection, almost all cells expressed green fluorescent protein (A). The GDNF gene expression in PB-GDNF-Sertoli cells was significantly higher than that in control Sertoli cells (B). The GDNF gene secretion in PB-GDNF-Sertoli cells was significantly higher than that in control Sertoli cells (C). Scale bars=500 μm.