Functional organization of protein determinants of meiotic DNA break hotspots

Sci Rep. 2017 May 3;7(1):1393. doi: 10.1038/s41598-017-00742-3.


During Schizosaccharomyces pombe meiotic prophase, homologous chromosomes are co-aligned by linear elements (LinEs) analogous to the axial elements of the synaptonemal complex (SC) in other organisms. LinE proteins also promote the formation of meiotic DNA double-strand breaks (DSBs), the precursors of cross-overs. Rec10 is required for essentially all DSBs and recombination, and three others (Rec25, Rec27, and Mug20) are protein determinants of DSB hotspots - they bind DSB hotspots with high specificity and are required for DSB formation there. These four LinE proteins co-localize in the nucleus in an interdependent way, suggesting they form a complex. We used random mutagenesis to uncover recombination-deficient missense mutants with novel properties. Some missense mutations changed essential residues conserved among Schizosaccharomyces species. DSB formation, gene conversion, and crossing-over were coordinately reduced in the mutants tested. Based on our mutant analysis, we revised the rec27 open reading frame: the new start codon is in the previously annotated first intron. Genetic and fluorescence-microscopy assays indicated that the Rec10 N- and C-terminal regions have complex interactions with Rec25. These mutants are a valuable resource to elucidate further how LinE proteins and the related SCs of other species regulate meiotic DSB formation to form crossovers crucial for meiosis.

Publication types

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

MeSH terms

  • Cell Cycle Proteins / genetics*
  • Cell Cycle Proteins / isolation & purification
  • DNA Breaks, Double-Stranded*
  • Gene Conversion
  • Introns
  • Meiosis*
  • Mutation, Missense
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / isolation & purification
  • Schizosaccharomyces / genetics
  • Schizosaccharomyces pombe Proteins / genetics*
  • Schizosaccharomyces pombe Proteins / isolation & purification


  • Cell Cycle Proteins
  • Mug20 protein, S pombe
  • Nuclear Proteins
  • REC10 protein, S pombe
  • Rec25 protein, S pombe
  • Rec27 protein, S pombe
  • Schizosaccharomyces pombe Proteins