These findings – published online: 22 January 2019 – suggest that histone modifications play a critical role in regulating gene expression in FGCs following DNA methylation erasure, leading to their differentiation into fFGCs and mFGCs. These findings provide a novel insight into the establishment of sex-specific epigenetic modifications in the germline, which is required for functional germ cell development. However, further study is needed to elucidate whether and how the various types of modifications interact.
Epigenetic signatures of germline cells are dynamically reprogrammed to induce appropriate differentiation, development and sex specification. We investigated sex-specific epigenetic changes in mouse fetal germ cells (FGCs) and neonatal germ cells.
Materials & methods:
Six histone marks in mouse E13.5 FGCs and P1 neonatal germ cells were analyzed by chromatin immunoprecipitation and sequencing. These datasets were compared with transposase-accessible chromatin sites, DNA methylation and transcriptome.
Different patterns of each histone mark were detected in female and male FGCs, and H3K4me3/H3K27me3 bivalent marks were enriched in different chromosomal regions of female and male FGCs.
Our results suggest that histone modifications may affect FGC gene expression following DNA methylation erasure, contributing to the differentiation into female and male germ cells.