P-114: The Study of 9-10 Days Mouse Embryo Forelimb Bud and Immature Oocyte Coculture on In Vitro Maturation

Background: Because of the problems of achieving to mature oocytes, abillity to deliver the oocytes to mature outside of ovaries was a big discovery that somewhat could reduce the risk of ART`s.Because of the low percentage of in vitro oocyte maturation, research for improving the IVM condition and increasing the oocyte maturation rate is to be continued. The aim of this research is the study of the effect of the factors released from mouse embryo forelimb formation on IVM conditions. Materials and Methods: 48hours after intraperitoneal injection of PMSG on NMRI female mice, ovaries immature oocytes were transferred to the base medium (αMEM supplemented with 20% FBS). Three experimental groups were considered to: 1. Base medium + 1 IU/mLi HCG, 2. Base medium coculture with 9-9.5 days mouse embryo forelimb bud and 3. Base medium coculture with 12-13 days mouse embryo forelimb. Oocytes after 24 hours of incubation, were indentified and counted in four groups as: MII, GVBD, GV and Degenerated. Results: Percentage of matured oocytes in control, experimental groups 1, 2 and 3, was 23.61% ± SE, 39.24% ± SE, 60% ± SE and 48.34% ± SE respectively. Oocytes maturation rate in experimental groups than the control group showed a significant increase (p<0.005). Conclusion: The coculture of oocytes with forelimb bud has significantly increased the maturation rate of unmatured oocytes. It is probably that the released paracrine factors during of forelimb formation has had significant effect on oocyte maturation and probably is most effective than the effect of presence of HCG endocrine factors in maturation culture medium during IVM process. It may be possible to recommend the use of forelimb co-culture or paracrine factors that release during forelimb formation for improving the IVM conditions.