MicroRNA-101 regulates oocyte maturation in vitro via targeting HAS2 in porcine cumulus cells

RNA-seq technology can be used for the detection of miRNA transcripts in tissues and cells at specific periods and under specific treatment conditions, which can easily and effectively screen out differential transcripts. The purpose of this study was to compare miRNA expression in porcine cumulus cells before and after oocyte maturation, and to investigate the mechanism whereby cumulus cells may influence oocyte maturation. To that aim, cumulus cells surrounding GV- and MII-stage oocytes were isolated, and their differences in miRNA expression were examined using miRNA-seq. 143 differentially expressed miRNAs were identified, among which miR-101 was selected and further verified by qPCR. Moreover, miR-101 was found to target HAS2 through target gene prediction, luciferase-based co-transfection and cumulus cells transfection. Transfection of COCs with miR-101 mimics or inhibitor revealed that the miR-101 could inhibit oocyte IVM by regulating the expanding of CCSs, but had no effect on the embryo development competence. These findings demonstrated that miR-101 regulated oocyte maturation in vitro via targeting HAS2 in porcine cumulus cells.