Conservation and divergence of meiotic DNA double strand break forming mechanisms in Arabidopsis thaliana

Nucleic Acids Res. 2021 Sep 27;49(17):9821-9835. doi: 10.1093/nar/gkab715.


In the current meiotic recombination initiation model, the SPO11 catalytic subunits associate with MTOPVIB to form a Topoisomerase VI-like complex that generates DNA double strand breaks (DSBs). Four additional proteins, PRD1/AtMEI1, PRD2/AtMEI4, PRD3/AtMER2 and the plant specific DFO are required for meiotic DSB formation. Here we show that (i) MTOPVIB and PRD1 provide the link between the catalytic sub-complex and the other DSB proteins, (ii) PRD3/AtMER2, while localized to the axis, does not assemble a canonical pre-DSB complex but establishes a direct link between the DSB-forming and resection machineries, (iii) DFO controls MTOPVIB foci formation and is part of a divergent RMM-like complex including PHS1/AtREC114 and PRD2/AtMEI4 but not PRD3/AtMER2, (iv) PHS1/AtREC114 is absolutely unnecessary for DSB formation despite having a conserved position within the DSB protein network and (v) MTOPVIB and PRD2/AtMEI4 interact directly with chromosome axis proteins to anchor the meiotic DSB machinery to the axis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis Proteins / metabolism*
  • Arabidopsis Proteins / physiology
  • Cell Cycle Proteins / metabolism
  • Chromatin / metabolism
  • DNA Breaks, Double-Stranded*
  • DNA Repair
  • DNA-Binding Proteins / metabolism
  • Meiosis / genetics*
  • Protein Tyrosine Phosphatases / physiology
  • Recombination, Genetic


  • ASY1 protein, Arabidopsis
  • ASY3 protein, Arabidopsis
  • Arabidopsis Proteins
  • Cell Cycle Proteins
  • Chromatin
  • DFO protein, Arabidopsis
  • DNA-Binding Proteins
  • Spo11-1 protein, Arabidopsis
  • PHS1 protein, Arabidopsis
  • Protein Tyrosine Phosphatases