The effect of insulin-like growth factor-1 on the proliferation of goat spermatogonial stem cells (SSCs) in vitro

This study aimed to the effect of insulin-like growth factor-1 on the proliferation of goat spermatogonial stem cells (SSCs) in vitro.

The testicles of immature goats were obtained from slaughterhouse. Isolation of spermatogonial cells was performed by two-step digestion. The isolated cells were cultured in 4 different groups: 3 groups by adding different doses of IGF-1 (10, 40 and 100 ng/ml) to the basic medium (DMEM containing 5% fetal bovine serum and 1% antibiotic) and the control group (without IGF-1). Data were analyzed by one-way ANOVA and Tukey test at 5% level. Presence of SSCs at the end of culture was determined by reverse transcription polymerase chain reaction (RT-PCR) for several important spermatogonial markers (PGP9.5, THY-1, PLZF, Oct4 and VASA) and immunohistochemical staining against PGP9.5 antigen.

In this study, the number of spermatogonial cell colonies in treatment 3 was significantly higher than the control and other treatment groups on days 4, 7, and 10 of culture (P<0.05). Also, the surface area of G10 colonies on days 7 and 10 of culture was significantly different (P<0.05). The surface area of G100 on days 4, 7, and 10 after culture was significantly higher than control, G10 and G40 (P<0.05). The isolated cells expressed all surface markers related to stem cells.

According to this results, the addition of 100 ng/ml IGF-1 to culture medium for promoting colonization of goat Spermatogonial stem cells is recommended.