The Effects Of NGF-beta On The Development Of Porcine Oocytes Cultured In Vitro

Nerve growth factor affect nerve cell growth and survival. In recent years, thestudy found that NGF and its receptors are also distributed in the reproductive axis,and affect animal reproductive physiology bydifferences inthe expression anddistribution. Cumulus cells also plays an extremely important role on oocytematuration, fertilization ability and post-embryonic development. The paper starts bythe two main lines of NGF and DOs, hoping to find the effects of the two factors onoocytes.Experiment1. Dos getting from class-A,class-C and unclassified COCs werecultured to observe the maturation rate.The results shows that the maturation rates ofby class-A COCs were the highest（41.52%）, and there were significant differencesbetween groups with class-C (18.23%)and unclassified COCs (26.13%).Experiment2.In vitro added NGF to Dos from class-A cumulus oocytecomplexes,the results shoued that there was no effect on the maturation anddegradation in different concentrations (1ng/mL,10ng/mL,100ng/mL).10ng/mLNGF (50.68%) was the highest,and there were significant differences with the controlgroup (25.96%), and100ng/mL NGF (29.31%) group in cleavage rate. Blastocystrates were all very low. Repeating experiment with class-C oocytes, it gets the sameresults.But the cleavage rates did not reach significant difference, it may be due toexperimental error or poor quality oocytes.Experiment3.In the pig oocyte maturation medium, different concentrationsNGF (1ng/mL,10ng/mL,100ng/mL) were added to observe maturation anddegeneration of oocytes,and degree of cumulus expansion.After parthenogenesis, thedevelopmentsituation of parthenogenetic embryos were observed.The results showedthat although10ng/mL NGFgroupimprove the maturation rate,but thedifference wasnot significant. The expansion of cumulus of mature oocytes showed100ng/mLNGFgroup was the lowest, and there were significant differences between groups with thecontrol group and10ng/mL NGF group.10ng/mL NGF group was the lowest in thedegradationrate, and was significant difference with100ng/mL NGFgroup(16.07%vs23.61%). Parthenogenetic embryos’development showed that10ng/mL NGFgroup was the highest in cleavage rate, blastocyst rate and blastocyst total cell number,and there were significant differences with100ng/mL NGF group in the cleavagerate(67.95%vs48.41%), and there were significant differences with the control groupin the blastocyst rate (42.31%vs19.03%). Experiment4. In order toinvestigat the action time of NGF on the COCs moreprecisely, mature time was cut in half, respectively added NGF with differentconcentrations (1ng/mL,10ng/mL,100ng/mL) in these two periods.The results showed that adding NGF in forward21hours all groups wereindifference to oocytes. Added in post21hours showed that10ng/mLNGF groupimproved maturation rate and reduced the degradation rate, but did not reachsignificant difference.Cleavage rate of10ng/mL NGF group (75.72%) was thehighest, and showed significant differences with100ng/mL NGF group (54.32%).Blastocyst rate of10ng/mL NGF group was the highest, but the difference was notsignificant.Experiment5. NGF with different concentrations (1ng/mL,10ng/mL,100ng/mL)added in the pig embryo culture medium.The result showed that there was no effecton the development of parthenogenetic embryos.