Effects of L-carnitine on oocytes in vitro maturation, lipid metabolism and parthenogenetic embryos development in porcine

【Objective】This study was conducted to explore the effect of different concentrations of L-carnitine on the maturation of porcine oocytes, the development of parthenogenetic (PA) embryos in vitro and the lipid metabolism in pig oocytes. 【Method】Different concentrations of L-carnitine were added into mature medium to observe the influence on porcine oocytes maturation and parthenogenetic embryos development. Oil red staining, triacylglycerol kit and quantitative RT-PCR were used to detect the lipid metabolism and the key hydrolase expression level in oocytes.【Result and conclusion】The rates of oocytes maturation and the subsequent PA blastocysts increased significantly when supplemented with 100 ng/mL L-carnitine to the IVM medium (P<0.05), and the oocytes lipid metabolism also increased significantly (P<0.001). The addition of 100 ng/mL L-carnitine into embryo culture medium significantly increased the cleavage rates (P<0.05) and contributed to the PA blastocyst rates and qualities. Further analyses of quantitative RT-PCR revealed that the mRNA expression levels of adipose triglyceride lipase gene (ATGL) and hormone-sensitive triglayceride lipase gene (HSL) both decreased significantly with 100 ng/mL L-carnitine treatment, which indicated that the L-carnitine could affect the lipid metabolism by regulating the key lipases gene expression. In conclusion, these results demonstrated that L-carnitine can improve porcine oocytes maturation and enhance the PA embryos developmental ability through lipid metabolism regulation.