Analysis Of The Expression Profile Of Yak KDM1A And Its Effect On Meiosis Maturation Of Oocyte

The yak,mainly living in Qinghai-Tibetan Plateau,is one of the mains of production for the people in the pasturing area.However,its seasonal estrus and low reproductive efficiency has seriously affected the economic income of local herders.In recent years,in order to improve this situation,a number of studies have been conducted by scholars on yak reproductive physiology.They found the quality of oocyte directly affects the embryo transfer,development,pregnancy rate and survival rate of yak after fertilization.Recent reports indicated the histone demethylase is involved in the regulation of oocyte maturation and developmental potential.And the expression level of KDM1 A is dynamic change during in the oocyte maturation and development process.However,the concrete regulation mechanism of KDM1 A in this process is still unclearly.Therefore,in this study,the yak KDM1 A gene sequence was successfully cloned and the tissues expression profile were clarified in this study.In addition,GSK-KDM1 A,the specific inhibitor of KDM1 A,was used to explore the correlation between KDM1 A and yak oocytes development.The results are as following: 1.The CDS region of KDM1 A was 2 401 bp.The homology results indicated that KDM1 A was relatively conservative in the evolutionary process.The tissues expression profile revealed that it was expressed in all selected tissues,especially in testis and liver.These results indicated that KDM1 A played a crucial role in yak physiological reproduction;2.The results of immunohistochemistry showed that KDM1 A was expressed in yak granulosa cells and oocytes.The expression level of KDM1 A in oocytes was dynamically detected by RT-qPCR.And the results showed that the expression level of KDM1 A in MI period oocyte was significantly lower than that in MII and GV period(P<0.01).,but their was no significantly in MII and GV period(P>0.05).These results indicated KDM1 A was involved in the meiosis maturation of yak oocytes.3.GSK-KDM1 A was used to detect the effects of KDM1 A on cumulus cells expansion,oocytes IVM and subsequent embryonic development competence.The COCs were cultured in the maturation medium containing different concentrations of GSK-KDM1 A for 24 h,and the results showed that the score of the cumulus cells expansion and maturation rate of oocytes in 160 nM and 320 nM treated groups were significantly lower than that in the control group(P<0.05).Then the treated oocytes were fertilized in vitro and the results showed that the cleavage rate in 160 nM and 320 nM GSK-KDM1 A treated groups was significant lower than that in the control group(P<0.05).While,there was no significant different in the blastocyst formation rate(P>0.05);The results of RT-qPCR showed that the inhibitor significantly down-regulated expression of KDM1A(P<0.01)and up-regulation the expression of OCT4 and SOX2(P<0.05),while the expression of NANOG had no significantly change(P>0.05).The results indicated KDM1 A might regulate the yak oocyte meiosis maturation by down-regulate the expression of KDM1 A,and affect oocyte in vitro maturation and developmental potential.In summary,the sequence of yak KDM1 A gene was obtained and it was relatively conservative in the evolutionary process.The KDM1 A gene was expressed in various tissues of yak,and relatively higher in the reproductive organs including ovary and testis.The above results revealed KDM1 A was closely related to yak reproductive physiology.After the addition of specific inhibitor,The yak oocyte in vitro maturation and developmental potential was significantly affected,which indicated that the KDM1 A gene might play an important role in yak oocyte development.However,its specific mechanism needs further study.This study provides a theoretical basis to research the function of yak KDM1 A gene and its role in physiological reproduction.