Comparison of RNA m6A and DNA methylation profiles between mouse female germline stem cells and STO cells

Abstract

N6-methyladenosine (m6A) methylation modification is the most prevalent and abundant internal modification of eukaryotic mRNAs. Increasing evidence has shown that mRNA m6A plays important roles in the development of stem cells. However, to the best of our knowledge, no reports about the roles of mRNA m6A in mouse female germline stem cells (mFGSCs) have been published. In this study, we compared the genome-wide profiles of mRNA m6A methylation and DNA methylation between FGSCs and sandosinbred mice (SIM) embryo-derived thioguanine and ouabain-resistant (STO) cells. qRT-PCR revealed that the expression levels of mRNA m6A-related genes (Mettl3, Alkbh5, Ythdf1, Ythdf2, Ythdc1, and Ythdc2) in FGSCs were significantly higher than those in STO cells. m6A RNA immunoprecipitation sequencing (MeRIP-seq) data further showed that the unique m6A-methylated mRNAs in FGSCs and STO cells were related to cell population proliferation and somatic development, respectively. Additionally, knockdown of Ythdf1 inhibited FGSC self-renewal. Comparison of methylated DNA immunoprecipitation sequencing (MeDIP-seq) results between FGSCs and STO cells identified that DNA methylation contributed to FGSC proliferation by suppressing the somatic program. These results suggested that m6A regulated FGSC self-renewal possibly through m6A binding protein YTHDF1, and DNA methylation repressed somatic programs in FGSCs to maintain FGSC characteristics.