The Function Of JARID2 In Bovine During Early Embryonic Development

Modification of histone lysine is an important epigenetic modification. It has been reported that histone lysine methyltransferase and demethylase have an important role in early embryo development. JARID2 is one of the Jumonji demethylase protein family, the regulator of early embryo development, can regulate mouse development and embryonic stem cells(ESCs) differentiation by modification of histone lysine. However, there are reported that JARID2 is different from the other members of Jumonji protein family, does not have demethylase activity. JARID2 could affect early embryo development by regulating methylation level of H3K27me3, and the methylation level of H3K27me3 is closely related with the normal of early embryo developmentIn order to investigate the expression pattern of JARID2 in bovine oocytes and early embryo development stage and the effect of H3K27me3 on bovine early embryo development induced by JARID2. This study was first detected JARID2 m RNA expression in bovine oocytes and different stages of early embryo by q RT-PCR. The results shown that JARID2 had a high level of expression in GV, MII, 2-cell stage, 4-cell stage, 8-cell stage, 16-cell stage, morula and blastocyst stage, but the relative expression level of JARID2 in bovine GV oocytes was significantly lower than the other stages(p<0.05). Meanwhile, this study cleared that expression location of JARID2 in bovine early embryos by immunofluorescence. The results shown that JARID2 is expressed in early embryo(2-cell stage to the blastocyst stage) acquired by vitro fertilization and the expression location mainly in the nucleus.Finally, we detected the m RNA expression level of embryonic development-relat ed genes(OCT4, SOX2 and c-myc) between JARID2-2830-si RNA group and negativ e control group by real-time PCR, imvestigating the molecular pathway of JARID2 in the early embryo development by regulating H3K27me3. The results showed that the relative expression level of OCT4, SOX2 and c-myc in 2-cell early embryos was significantly higher than blastocyst stage, and the m RNA expression level of these embryo nic development-related genes was significantly increased after inhibiting JARID2 exp ression by JARID2-2830-si RNA microinjection. It suggested that JARID2 may play a key role in the early embryonic development by regulating the expression of these ge nes via mediating H3K27me3 expression.In summary, the study identified the expression pattern of JARID2 in bovine ooc ytes and each stages of the early embryo after in vitro fertilization, and the effect of J ARID2-mediated H3K27me3 on the development of the bovine early embryo. It also suggested that the function of histone lysine methylatipn and demethylationmodificati on in bovine oocytes and early embryos. The results provided a new idea for improvin g the efficiency of embryo culture in vitro, and a theoretical basis for further studying the regulating mechanism of the development in early embryo.