Effect of insulin and leukemia inhibit factor on in vitro maturation and parthenogenetic development of porcine oocytes

To evaluate the effects of supplementation of Insulin and leukemia inhibit factor(LIF) in culture media on in vitro nuclear maturation of porcine oocytes and in vitro development of porcine parthenotes.1) Insulin or LIF was added into the medium of porcine oocytes in vitro maturation;and the matured oocytes with the first poly body were recorded and parthenogentically activated followed by being cultured in vitro in normal medium;2) Insulin or LIF was supplemented into parthenotes in vitro culture medium;and the rates of cleavage and blastocyst formation were recorded.For in vitro maturation,supplementation of 5μg/mL insulin significantly increased the rate of in vitro nuclear maturation of pig oocytes although subsequent in vitro development of these oocytes was similar to the control after parthenogenetic activation.When LIF was added,no obvious increase of nuclear maturation was found whereas the blastocyst rate decreased drastically of such oocytes after parthenogenetic activation.When insulin was only added to culture medium of parthenotes,no beneficial effect was observed regarding to cleavage and blastocyst formation.When LIF was singly supplemented to embryo culture medium,very slight,and not significant increase of the cleavage and blastocyst rates was found.Insulin was confirmed conducive to the maturation of porcine oocytes,but further studies are required to investigate if other concentrations or treatments of insulin are helpful to porcine parthnotes development in vitro.Regarding to LIF,it is harmful to blastocyst development in vitro.However,more concentrations and treatments of LIF are deserved to be examined whether it could promote maturation and in vitro development of porcine embryos or not.