Mito-Q supplementation of in vitro maturation or in vitro culture medium improves maturation of buffalo oocytes and developmental competence of cloned embryos by reducing ROS production

Abstract

Mito-Q is a well-known mitochondria-specific superoxide scavenger. To our knowledge, the effect of Mito-Q on buffalo oocyte maturation and developmental competency of cloned embryos has not been examined. To investigate the effects of Mito-Q on the in vitro maturation (IVM) of buffalo oocytes and the developmental competence of cloned embryos, different concentration of Mito-Q were supplemented with IVM (0, 0.1, 0.5, 1, 2 μM) and in vitro culture (IVC) medium (0, 0.1 μM). Supplementation of IVM medium with 0.1 μM Mito-Q significantly (P ≤ 0.05) increased the cumulus expansion, nuclear maturation, mitochondrial membrane potential (MMP) and antioxidants genes (GPX1 and SOD2) expression and effectively reduced ROS production leading to a significant improvement in the maturation rate of buffalo oocytes. Further, the supplementation of 0.1 μM Mito-Q in IVC medium promotes the cleavage and blastocyst rate significantly over the control. Mito-Q supplementation improves (P ≤ 0.05) MMP, antioxidant gene (GPX1) expression and reduced the ROS level and apoptosis related genes (caspase 9) expression in cloned blastocysts. In conclusion, the present study demonstrated that the supplementation of 0.1 μM Mito-Q in IVM and IVC media exerts a protective role against oxidative stress by reducing ROS production and improving MMP, fostering improved maturation of buffalo oocytes and enhanced developmental competence of cloned embryos. These findings contribute valuable insights into the optimization of assisted reproductive technologies protocols for buffalo breeding and potentially offer novel strategies to enhance reproductive outcomes in livestock species.

Keywords: Antioxidant; Buffalo; Embryo; Oocyte; Reactive oxygen species.