Abstract:

The study aimed to investigate the expression pattern of miR-215-5p in tissues of Leizhou black ducks and verify the regulatory effect of miR-215-5p on the proliferation and apoptosis of follicular granulosa cells. Three 43-week-old egg-laying and three 51-week-old non-laying Leizhou black ducks with similar body weight and health conditions were selected. The expression levels of miR-215-5p in different tissues were detected using RT-qPCR. By constructing mimics and interference fragment vectors and transfecting them into follicular granulosa cells, cell proliferation and apoptosis were detected using CCK-8 and flow cytometry techniques, with each group containing 3 replicates. The results showed that the expression of miR-215-5p in egg-laying Leizhou black ducks was generally higher than that in non-laying ducks, with relatively high expression in the ovary, infundibulum, and breast leg muscles, and relatively low expression in the funnel part, uterus, and heart. CCK-8 and EdU assays showed that miR-215-5p inhibited the proliferation of follicular granulosa cells; flow cytometry detected that miR-215-5p promoted the apoptosis of follicular granulosa cells; RT-qPCR detection of proliferation and apoptosis marker genes expression showed that after transfection with miR-215-5p mimics, the expression levels of CCND1 and CDK2 were both significantly decreased (P < 0.01), and Caspase-3 was significantly increased (P < 0.01); while after transfection with miR-215-5p interference fragments, CCND1 was significantly increased (P < 0.05), CDK2 was significantly increased (P < 0.01), Caspase-3 was significantly decreased (P < 0.01), and TP63 was significantly decreased (P < 0.05). miR-215-5p in Leizhou black duck has the ability to restrain the proliferation of follicular granulosa cells and promote their apoptosis.

Key words: Leizhou black duck, miR-215-5p, miRNA, granulosa cells, proliferation and apoptosis