COL1A1 may be associated with lambing traits in goats by regulating the biological function of ovarian granulosa cells via the PI3K/AKT/mTOR signalling pathway

Collagen type I alpha 1 chain (COL1A1), an important component of type I collagen protein, plays a role in regulating follicle development and ovarian cell proliferation, which is closely related to animal reproductive traits. The aim of this study was to explore the relationship between the expression of COL1A1 and lambing traits of Guizhou black goats (Capra hircus), and regulatory mechanisms in follicle development. Results showed that the protein expression level of COL1A1 in ovarian tissues of the polytocous group were higher than those of the monotocous group, and COL1A1 was expressed in all follicles and ovarian cells. Upregulation of COL1A1 significantly promoted cell proliferation, migration and the development of cells from G1 to G2/M phase, reduced intracellular ROS levels. Additionally, COL1A1 overexpression resulted in significantly increased expression of proliferating cell nuclear antigen (PCNA) and the ratios of p-PI3K (phosphorylation-phosphatidylinositol 3-kinase)/PI3K, p-AKT (phosphorylation-protein kinase B)/AKT and p-mTOR (phosphorylation-mammalian target of rapamycin) /mTOR, and decreased expression of BCL2-Associated X (BAX), caspase-3 and caspase-9. The reverse result, however, was seen when COL1A1 expression was downregulated in granulosa cells. Taken together, COL1A1 was widely and highly expressed in ovarian tissues of polytocous goats, and it may participate in regulations of lambing traits by regulating the proliferation and migration of granulosa cells by activating the PI3K/AKT/mTOR signalling pathway and reducing ROS production in granulosa cells to facilitate the development and maturation of follicle.