Function of JARID2 in bovines during early embryonic development.

Yao Fu,Xu-Lei Sun,Hao Jiang,Chang Liu,Yan Gao,Jia-Bao Zhang,Jia-Jun Xu,Bao Yuan,Dong-Xu Han

doi:10.7717/peerj.4189

Abstract

Histone lysine modifications are important epigenetic modifications in early embryonic development. JARID2, which is a member of the jumonji demethylase protein family, is a regulator of early embryonic development and can regulate mouse development and embryonic stem cell (ESC) differentiation by modifying histone lysines. JARID2 can affect early embryonic development by regulating the methylation level of H3K27me3, which is closely related to normal early embryonic development. To investigate the expression pattern of JARID2 and the effect of JARID2-induced H3K27 methylation in bovine oocytes and early embryonic stages, JARID2 mRNA expression and localization were detected in bovine oocytes and early embryos via qRT-PCR and immunofluorescence in the present study. The results showed that JARID2 is highly expressed in the germinal vesicle (GV), MII, 2-cell, 4-cell, 8-cell, 16-cell and blastocyst stages, but the relative expression level of JARID2 in bovine GV oocytes is significantly lower than that at other oocyte/embryonic stages (p < 0.05), and JARID2 is expressed primarily in the nucleus. We next detected the mRNA expression levels of embryonic development-related genes (OCT4, SOX2 and c-myc) after JARID2 knockdown through JARID2-2830-siRNA microinjection to investigate the molecularpathwayunderlying the regulation of H3K27me3 by JARID2 during early embryonic development. The results showed that the relative expression levels of these genes in 2-cell embryos weresignificantly higher than those in the blastocyst stage, and expression levels were significantly increased after JARID2 knockdown. In summary, the present study identified the expression pattern of JARID2 in bovine oocytes and at each early embryonic stage, and the results suggest that JARID2 plays a key role in early embryonic development by regulating the expression of OCT4, SOX2 and c-myc via modification of H3K27me3 expression. This work provides new data for improvements in the efficiency of in vitro embryo culture as well as a theoretical basis for further studying the regulatory mechanisms involved in early embryonic development.

Highlights

Epigenetic modifications are common biological phenomena involved in gene regulation and are essential for maintaining the normal physiological activities of mammals
The results showed that the expression of H3K27me3 in the JARID2 siRNA silencing group at the 2-cell stage, Figure 4 JARID2 knockdown affects histone H3K27 methylation at the 2-cell, 4-cell, 8-cell and blastula stages. (A) H3K27me3 immunofluorescence staining in the negative control group; green FITC fluorescence represents H3K27me3 expression, and blue DAPI fluorescence represents the location of DNA in the cell nucleus
Our results demonstrate that JARID2 acts as an important transcription factor or regulatory protein that affects the development of oocytes and embryos, and it may be involved in epigenetic modification

Summary

Introduction

Epigenetic modifications are common biological phenomena involved in gene regulation and are essential for maintaining the normal physiological activities of mammals. How to cite this article Fu et al (2017), Function of JARID2 in bovines during early embryonic development. Many studies have shown that changes in a variety of epigenetic modifications occur during mammalian embryonic development. Embryonic development is the period in which cell division and differentiation are most active, and there is large-scale transcription of zygotic genes. At this stage, genes are subject to activation and inhibition under the control of signals from both inside and outside of cells, and many regulatory mechanisms participate in their regulation. Studies conducted in recent years have increasingly shown that epigenetic regulation plays an important role during mammalian embryonic development

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