Dgcr8 and Dicer are essential for sex chromosome integrity during meiosis in males

J Cell Sci. 2015 Jun 15;128(12):2314-27. doi: 10.1242/jcs.167148. Epub 2015 May 1.


Small RNAs play crucial roles in regulating gene expression during mammalian meiosis. To investigate the function of microRNAs (miRNAs) and small interfering RNAs (siRNAs) during meiosis in males, we generated germ-cell-specific conditional deletions of Dgcr8 and Dicer in mice. Analysis of spermatocytes from both conditional knockout lines revealed that there were frequent chromosomal fusions during meiosis, always involving one or both sex chromosomes. RNA sequencing indicates upregulation of Atm in spermatocytes from miRNA-deficient mice, and immunofluorescence imaging demonstrates an increased abundance of activated ATM kinase and mislocalization of phosphorylated MDC1, an ATM phosphorylation substrate. The Atm 3'UTR contains many potential microRNA target sites, and, notably, target sites for several miRNAs depleted in both conditional knockout mice were highly effective at promoting repression. RNF8, a telomere-associated protein whose localization is controlled by the MDC1-ATM kinase cascade, normally associates with the sex chromosomes during pachytene, but in both conditional knockouts redistributed to the autosomes. Taken together, these results suggest that Atm dysregulation in microRNA-deficient germ lines contributes to the redistribution of proteins involved in chromosomal stability from the sex chromosomes to the autosomes, resulting in sex chromosome fusions during meiotic prophase I.

Keywords: Dgcr8; Dicer; Dicer1; Germ line; Meiosis; MicroRNA; Sex body; Sex chromosomes; Telomere.

Publication types

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

MeSH terms

  • Animals
  • Ataxia Telangiectasia Mutated Proteins / genetics
  • Ataxia Telangiectasia Mutated Proteins / metabolism*
  • Cells, Cultured
  • DEAD-box RNA Helicases / physiology*
  • Female
  • Male
  • Meiosis / physiology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • MicroRNAs / genetics*
  • RNA, Messenger / genetics
  • RNA-Binding Proteins / physiology*
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Ribonuclease III / physiology*
  • Sex Chromosomes / physiology*
  • Spermatocytes / cytology
  • Spermatocytes / physiology*


  • Dgcr8 protein, mouse
  • MicroRNAs
  • RNA, Messenger
  • RNA-Binding Proteins
  • Ataxia Telangiectasia Mutated Proteins
  • Dicer1 protein, mouse
  • Ribonuclease III
  • DEAD-box RNA Helicases