title: RMI1 and TOP3α limit meiotic CO formation through their C-terminal domains.
abstract: At meiosis, hundreds of programmed DNA double-strand breaks (DSBs) form and are repaired by homologous recombination. From this large number of DSBs, only a subset yields crossovers (COs), with a minimum of one CO per chromosome pair. All DSBs must be repaired and every recombination intermediate must be resolved to avoid subsequent entanglement and chromosome breakage. The conserved BLM-TOP3α-RMI1 (BTR) complex acts on early and late meiotic recombination intermediates to both limit CO outcome and promote chromosome integrity. In Arabidopsis, the BLM homologues RECQ4A and RECQ4B act redundantly to prevent meiotic extra COs, but recombination intermediates are fully resolved in their absence. In contrast, TOP3α is needed for both processes. Here we show through the characterization of specific mutants that RMI1 is a major anti-CO factor, in addition to being essential to prevent chromosome breakage and entanglement. Further, our findings suggest a specific role of the C-terminal domains of RMI1 and TOP3α, that respectively contain an Oligo Binding domain (OB2) and ZINC finger motifs, in preventing extra-CO. We propose that these domains of TOP3α and RMI1 define a sub-domain of the BTR complex which is dispensable for the resolution of recombination intermediates but crucial to limit extra-COs.
authors.affiliation: Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78000 Versailles, France.
authors.forename: Mathilde
authors.initials: M
authors.lastname: Séguéla-Arnaud
authors.affiliation: Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78000 Versailles, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Choinard
authors.affiliation: Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78000 Versailles, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Larchevêque
authors.affiliation: Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78000 Versailles, France.
authors.forename: Chloé
authors.initials: C
authors.lastname: Girard
authors.affiliation: Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78000 Versailles, France.
authors.forename: Nicole
authors.initials: N
authors.lastname: Froger
authors.affiliation: Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78000 Versailles, France.
authors.forename: Wayne
authors.initials: W
authors.lastname: Crismani
authors.affiliation: Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, Université Paris-Saclay, RD10, 78000 Versailles, France.
authors.forename: Raphael
authors.initials: R
authors.lastname: Mercier
mesh_terms: D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D003434:Crossing Over, Genetic; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D004264:DNA Topoisomerases, Type I / Q000737:chemistry / Q000378:metabolism*; D004843:Epistasis, Genetic; D008540:Meiosis; D008954:Models, Biological; D009154:Mutation; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D011995:Recombination, Genetic; D016335:Zinc Fingers
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; C534772:RMI1 protein, Arabidopsis; D004265:DNA Helicases; C573664:FANCM protein, Arabidopsis; D004264:DNA Topoisomerases, Type I