Dnmt2-null sperm block maternal transmission of a paramutant phenotype†

Biol Reprod. 2021 Sep 14;105(3):603-612. doi: 10.1093/biolre/ioab086.

Abstract

Previous studies have shown that Dnmt2-null sperm block the paternal transmission (through sperm) of certain acquired traits, e.g., high-fat diet-induced metabolic disorders or white tails due to a Kit paramutation. Here, we report that DNMT2 is also required for the transmission of a Kit paramutant phenotype (white tail tip) through the female germline (i.e., oocytes). Specifically, ablation of Dnmt2 led to aberrant profiles of tRNA-derived small RNAs (tsRNAs) and other small noncoding RNAs (sncRNAs) in sperm, which correlate with altered mRNA transcriptomes in pronuclear zygotes derived from wild-type oocytes carrying the Kit paramutation and a complete blockage of transmission of the paramutant phenotype through oocytes. Together, the present study suggests that both paternal and maternal transmissions of epigenetic phenotypes require intact DNMT2 functions in the male germline.

Keywords: acquired trait; epigenetic inheritance; epigenetics; fertilization; oocytes; paramutation; reprogramming; sperm; tRNA fragments.

Publication types

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

MeSH terms

  • Animals
  • Color
  • DNA (Cytosine-5-)-Methyltransferases / deficiency*
  • DNA (Cytosine-5-)-Methyltransferases / metabolism
  • Epigenesis, Genetic*
  • Female
  • Male
  • Mice / genetics*
  • Mutation*
  • Phenotype
  • Pigmentation / genetics*
  • Proto-Oncogene Proteins c-kit / genetics*
  • Tail / physiology*

Substances

  • Kit protein, mouse
  • Dnmt2 protein, mouse
  • DNA (Cytosine-5-)-Methyltransferases
  • Proto-Oncogene Proteins c-kit