MSH2 shapes the meiotic crossover landscape in relation to interhomolog polymorphism in Arabidopsis.

Autor: Blackwell AR; Department of Plant Sciences, University of Cambridge, Cambridge, UK., Dluzewska J; Laboratory of Genome Biology, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan, Poland., Szymanska-Lejman M; Laboratory of Genome Biology, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan, Poland., Desjardins S; Department of Genetics and Genome Biology, University of Leicester, Leicester, UK., Tock AJ; Department of Plant Sciences, University of Cambridge, Cambridge, UK., Kbiri N; Laboratory of Genome Biology, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan, Poland., Lambing C; Department of Plant Sciences, University of Cambridge, Cambridge, UK., Lawrence EJ; Department of Plant Sciences, University of Cambridge, Cambridge, UK., Bieluszewski T; Laboratory of Genome Biology, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan, Poland., Rowan B; Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany., Higgins JD; Department of Genetics and Genome Biology, University of Leicester, Leicester, UK., Ziolkowski PA; Laboratory of Genome Biology, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan, Poland., Henderson IR; Department of Plant Sciences, University of Cambridge, Cambridge, UK.
Jazyk: angličtina
Zdroj: The EMBO journal [EMBO J] 2020 Nov 02; Vol. 39 (21), pp. e104858. Date of Electronic Publication: 2020 Sep 16.
DOI: 10.15252/embj.2020104858
Abstrakt: During meiosis, DNA double-strand breaks undergo interhomolog repair to yield crossovers between homologous chromosomes. To investigate how interhomolog sequence polymorphism affects crossovers, we sequenced multiple recombinant populations of the model plant Arabidopsis thaliana. Crossovers were elevated in the diverse pericentromeric regions, showing a local preference for polymorphic regions. We provide evidence that crossover association with elevated diversity is mediated via the Class I crossover formation pathway, although very high levels of diversity suppress crossovers. Interhomolog polymorphism causes mismatches in recombining molecules, which can be detected by MutS homolog (MSH) mismatch repair protein heterodimers. Therefore, we mapped crossovers in a msh2 mutant, defective in mismatch recognition, using multiple hybrid backgrounds. Although total crossover numbers were unchanged in msh2 mutants, recombination was remodelled from the diverse pericentromeres towards the less-polymorphic sub-telomeric regions. Juxtaposition of megabase heterozygous and homozygous regions causes crossover remodelling towards the heterozygous regions in wild type Arabidopsis, but not in msh2 mutants. Immunostaining showed that MSH2 protein accumulates on meiotic chromosomes during prophase I, consistent with MSH2 regulating meiotic recombination. Our results reveal a pro-crossover role for MSH2 in regions of higher sequence diversity in A. thaliana.
(© 2020 The Authors. Published under the terms of the CC BY 4.0 license.)
Databáze: MEDLINE
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