SEMA4G targeted by miR-363-5p regulates the proliferation of granulosa cells in Yunshang black goats

Proliferation of granular cells (GCs) plays an important role in ovary development, providing energy and a microenvironment for oocyte ovulation. In this study, we explored the spatiotemporal expression of SEMA4G and its effects on the growth and development of goat GCs using primary GCs cultured in vitro as a model. The results showed that the expression level of SEMA4G was significantly higher in the ovaries of high-fertility goats than in those of low-fertility goats (p < 0.05). The mRNA and protein expression levels of the cell proliferation markers of GCs were significantly increased after the overexpression of SEMA4G in goat primary GCs. The EdU and CCK8 results showed that cell viability was elevated in goat GCs and that proliferation was promoted by an increase in the number of proliferating cells. The proliferation of goat GCs was significantly inhibited by SEMA4G inhibition (p < 0.05). The results of online miRNA and target gene prediction software and dual luciferase activity analysis confirmed that SEMA4G could bind to mi-363-5p and was one of its target genes. The RT‒qPCR results showed that the expression level of miR-363-5p was significantly lower in the ovaries of high-fertility goats than in those of low-fertility goats in contrast to the expression level of SEMA4G (p < 0.05). After the overexpression of miR-363-5p in goat GCs, the expression of SEMA4G was significantly suppressed (p < 0.05). Collectively, the results of this study could lay the foundation for exploring the molecular mechanisms by which SEMA4G and miR-363-5p regulate the growth and development of goat GCs and provide targets for breeding high-fertility goats.