The Configuration of RPA, RAD51, and DMC1 Binding in Meiosis Reveals the Nature of Critical Recombination Intermediates

Mol Cell. 2020 Aug 20;79(4):689-701.e10. doi: 10.1016/j.molcel.2020.06.015. Epub 2020 Jun 30.

Abstract

Meiotic recombination proceeds via binding of RPA, RAD51, and DMC1 to single-stranded DNA (ssDNA) substrates created after formation of programmed DNA double-strand breaks. Here we report high-resolution in vivo maps of RPA and RAD51 in meiosis, mapping their binding locations and lifespans to individual homologous chromosomes using a genetically engineered hybrid mouse. Together with high-resolution microscopy and DMC1 binding maps, we show that DMC1 and RAD51 have distinct spatial localization on ssDNA: DMC1 binds near the break site, and RAD51 binds away from it. We characterize inter-homolog recombination intermediates bound by RPA in vivo, with properties expected for the critical displacement loop (D-loop) intermediates. These data support the hypothesis that DMC1, not RAD51, performs strand exchange in mammalian meiosis. RPA-bound D-loops can be resolved as crossovers or non-crossovers, but crossover-destined D-loops may have longer lifespans. D-loops resemble crossover gene conversions in size, but their extent is similar in both repair pathways.

Keywords: D-loop; DMC1; DNA double-strand breaks; DNA repair; RAD51; RPA; crossover; meiosis; recombination; strand invasion.

Publication types

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

MeSH terms

  • Animals
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Chromosomes / genetics
  • Chromosomes / metabolism
  • Crossing Over, Genetic
  • DNA, Single-Stranded / metabolism
  • Genome
  • Homologous Recombination*
  • Male
  • Meiosis*
  • Mice, Inbred C57BL
  • Mice, Inbred DBA
  • Phosphate-Binding Proteins / genetics
  • Phosphate-Binding Proteins / metabolism*
  • Rad51 Recombinase / genetics
  • Rad51 Recombinase / metabolism*
  • Replication Protein A / genetics
  • Replication Protein A / metabolism*
  • Testis

Substances

  • Cell Cycle Proteins
  • DNA, Single-Stranded
  • Dmc1 protein, mouse
  • Phosphate-Binding Proteins
  • Replication Protein A
  • Rpa1 protein, mouse
  • Rad51 Recombinase
  • Rad51 protein, mouse