Leptin supplementation in vitro improved developmental competence of buffalo oocytes and embryos.

The aim of the present study was to determine potential role of leptin on in vitro developmental competence of buffalo oocytes and embryos. Slaughterhouse derived culture grade buffalo cumulus oocyte complexes (COCs) were matured in vitro (IVM) with leptin (10 ng/ml) or without leptin (control). In each experiment, a pool of matured COCs was used for further in vitro embryo production and another pool of COCs was used for cumulus cells and mature oocytes isolation to study the relative mRNA expression of developmentally important genes. Presumptive zygotes were cultured in embryo culture (IVC) media supplemented with leptin (10 ng/ml) or without leptin (control). Cleavage rate was higher (p < 0.05) when leptin was supplemented during IVM + IVC, both, as compared to other groups. Higher cleavage rate was observed in leptin-treated groups, though it was non-significant. Blastocyst rate was higher (p < 0.05) in all the leptin treated groups. The relative mRNA expression of LEPR (Ob-Rb), HAS2 and EGFR was significantly (p < 0.05) up-regulated and the expression of CASPASE3 was down-regulated in cumulus cells of leptin-treated groups. The expression of GDF9, BMP15, GLUT1, LEPR and CASPASE3 transcripts in leptin and non-treated oocytes did not differ. The relative mRNA expression of POU5F1and LEPR transcripts in blastocysts was higher (p < 0.05) in leptin-treated groups; the change in expression of GLUT1, INF-τ and CASPASE3 transcripts was not significant (p > 0.05). Thus, it is concluded that leptin promotes developmental competence of bubaline oocytes by modulating cumulus enabling factors and genes regulating pluripotentcy in the blastocysts.