Small RNA class transition from siRNA/piRNA to miRNA during pre-implantation mouse development

Nucleic Acids Res. 2010 Aug;38(15):5141-51. doi: 10.1093/nar/gkq229. Epub 2010 Apr 12.


Recent studies showed that small interfering RNAs (siRNAs) and Piwi-interacting RNA (piRNA) in mammalian germ cells play important roles in retrotransposon silencing and gametogenesis. However, subsequent contribution of those small RNAs to early mammalian development remains poorly understood. We investigated the expression profiles of small RNAs in mouse metaphase II oocytes, 8-16-cell stage embryos, blastocysts and the pluripotent inner cell mass (ICM) using high-throughput pyrosequencing. Here, we show that during pre-implantation development a major small RNA class changes from retrotransposon-derived small RNAs containing siRNAs and piRNAs to zygotically synthesized microRNAs (miRNAs). Some siRNAs and piRNAs are transiently upregulated and directed against specific retrotransposon classes. We also identified miRNAs expression profiles characteristic of the ICM and trophectoderm (TE) cells. Taken together, our current study reveals a major reprogramming of functional small RNAs during early mouse development from oocyte to blastocyst.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blastocyst / metabolism*
  • Blastocyst Inner Cell Mass / metabolism
  • Cells, Cultured
  • DEAD-box RNA Helicases / antagonists & inhibitors
  • Embryonic Development / genetics*
  • Endoribonucleases / antagonists & inhibitors
  • Female
  • Mice
  • Mice, Inbred ICR
  • MicroRNAs / metabolism*
  • Oocytes / metabolism
  • RNA Interference
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism*
  • Retroelements
  • Ribonuclease III


  • MicroRNAs
  • RNA, Small Interfering
  • Retroelements
  • Endoribonucleases
  • Dicer1 protein, mouse
  • Ribonuclease III
  • DEAD-box RNA Helicases