GSE60875
PRMT5 protects genomic integrity during global DNA demethylation in primordial germ cells and preimplantation embryos
Primordial germ cells (PGCs) and preimplantation embryos undergo epigenetic reprogramming, which entails comprehensive erasure of DNA methylation. We found that PRMT5, an arginine methyltransferase, translocates from the cytoplasm to the nucleus during this process. Here we show that conditional loss of PRMT5 in early PGCs caused complete male and female sterility, which is preceded by upregulation of LINE1 and IAP transposons and DNA damage response. Similarly, loss of maternal-zygotic PRMT5 also leads to IAP upregulation and early embryonic lethality. We detected the PRMT5-catalysed repressive H2A/H4R3me2s modification on LINE1 and IAP in early wildtype PGCs, directly implicating this mark in the maintenance of transposon silencing during DNA hypomethylation. PRMT5 subsequently translocates back to the cytoplasm of PGCs to participate in the previously described PIWI-interacting RNA (piRNA) pathway that promotes transposon silencing via de novo DNA re-methylation. Thus, PRMT5 has a novel direct role in genome defense during preimplantation development and in PGCs at the time of global DNA demethylation Overall design: PGCs mRNA profiles of embryonic day 11.5 dpc control (Blimp1Cre;Prmt5flox/+) and Prmt5 germ cell knockout (Blimp1Cre;Prmt5 flox/flox) were generated by deep sequencing (SOLiD next generation sequencing).