Two waves of de novo methylation during mouse germ cell development

Genes Dev. 2014 Jul 15;28(14):1544-9. doi: 10.1101/gad.244350.114.


During development, mammalian germ cells reprogram their epigenomes via a genome-wide erasure and de novo rewriting of DNA methylation marks. We know little of how methylation patterns are specifically determined. The piRNA pathway is thought to target the bulk of retrotransposon methylation. Here we show that most retrotransposon sequences are modified by default de novo methylation. However, potentially active retrotransposon copies evade this initial wave, likely mimicking features of protein-coding genes. These elements remain transcriptionally active and become targets of piRNA-mediated methylation. Thus, we posit that these two waves play essential roles in resetting germ cell epigenomes at each generation.

Keywords: DNA methylation; LINE; LTR; germ cells; piRNA; retrotransposon.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cellular Reprogramming / genetics
  • DNA Methylation*
  • Epigenesis, Genetic / genetics
  • Male
  • Mice
  • RNA, Small Interfering / metabolism
  • Retroelements / genetics*
  • Spermatocytes / cytology*
  • Spermatocytes / metabolism
  • Spermatogenesis / genetics*
  • Transcription, Genetic


  • RNA, Small Interfering
  • Retroelements

Associated data

  • SRA/SRP037785
  • SRA/SRP037807
  • SRA/SRP037987