Genome binding/occupancy profiling by high throughput sequencing Expression profiling by high throughput sequencing Methylation profiling by high throughput sequencing
Summary
While de novo DNA methylation (DNAme) in mammalian germ cells is dependent upon DNMT3A and DNMT3L, oocytes and spermatozoa show distinct patterns of DNAme. In mouse oocytes, de novo DNAme requires the lysine methyltransferase (KMTase) SETD2, which deposits H3K36me3. Surprisingly, we show here that SETD2 is dispensable for de novo DNAme in the male germline. Rather, the KMTase NSD1, which broadly deposits H3K36me2 in euchromatic regions, plays a critical role in de novo DNAme in prospermatogonia, including of imprinted genes. However, males deficient in germline NSD1 show a more severe defect in spermatogenesis than Dnmt3l-/- males. Furthermore, unlike DNMT3L, NSD1 safeguards a subset of genes against H3K27me3-associated transcriptional silencing. In contrast, H3K36me2 plays only a minor role in de novo DNAme during oogenesis and females with NSD1 deficient oocytes are fertile. Thus, the sexually dimorphic pattern of DNAme in mature mouse gametes is driven by distinct profiles of H3K36 methylation.
Overall design
ChIP-seq from control and Setd2 KO, Nsd1 KO or Dnmt3l KO prospermaogonia at E16.5 and P0. WGBS (PBAT) in control and Setd2 KO or Nsd1 KO prospermaogonia at E16.5 and P0. RNA-seq from control and Nsd1 KO or Dnmt3l KO prospermatogonia at E16.5 and P0.