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Interhomolog polymorphism shapes meiotic crossover within the Arabidopsis RAC1 and RPP13 disease resistance genes.

Published version
Peer-reviewed

Type

Article

Change log

Authors

Serra, Heïdi 
Zhao, Xiaohui 
Blackwell, Alexander R  ORCID logo  https://orcid.org/0000-0002-0369-4584

Abstract

During meiosis, chromosomes undergo DNA double-strand breaks (DSBs), which can be repaired using a homologous chromosome to produce crossovers. Meiotic recombination frequency is variable along chromosomes and tends to concentrate in narrow hotspots. We mapped crossover hotspots located in the Arabidopsis thaliana RAC1 and RPP13 disease resistance genes, using varying haplotypic combinations. We observed a negative non-linear relationship between interhomolog divergence and crossover frequency within the hotspots, consistent with polymorphism locally suppressing crossover repair of DSBs. The fancm, recq4a recq4b, figl1 and msh2 mutants, or lines with increased HEI10 dosage, are known to show increased crossovers throughout the genome. Surprisingly, RAC1 crossovers were either unchanged or decreased in these genetic backgrounds, showing that chromosome location and local chromatin environment are important for regulation of crossover activity. We employed deep sequencing of crossovers to examine recombination topology within RAC1, in wild type, fancm, recq4a recq4b and fancm recq4a recq4b backgrounds. The RAC1 recombination landscape was broadly conserved in the anti-crossover mutants and showed a negative relationship with interhomolog divergence. However, crossovers at the RAC1 5'-end were relatively suppressed in recq4a recq4b backgrounds, further indicating that local context may influence recombination outcomes. Our results demonstrate the importance of interhomolog divergence in shaping recombination within plant disease resistance genes and crossover hotspots.

Description

Keywords

Arabidopsis, Arabidopsis Proteins, Chromatin, Chromosomes, Plant, Crossing Over, Genetic, DNA Breaks, Double-Stranded, Disease Resistance, Genes, Plant, High-Throughput Nucleotide Sequencing, Homologous Recombination, Meiosis, Mutation, Plant Diseases, Plants, Genetically Modified, Polymorphism, Genetic

Journal Title

PLoS Genet

Conference Name

Journal ISSN

1553-7390
1553-7404

Volume Title

14

Publisher

Public Library of Science (PLoS)
Sponsorship
The Royal Society (uf0762030)
Isaac Newton Trust (1026(ab))
Gatsby Charitable Foundation (GAT2962)
Biotechnology and Biological Sciences Research Council (BB/K007882/1)
Biotechnology and Biological Sciences Research Council (BB/L006847/1)
Biotechnology and Biological Sciences Research Council (BB/M004937/1)
The Royal Society (uf120133)
Gatsby Charitable Foundation (GAT3401)
Biotechnology and Biological Sciences Research Council (BB/N007557/1)
European Research Council (681987)
Research was supported by a Royal Society University Research Fellowship, the Gatsby Charitable Foundation grant GAT2962, BBSRC grant BB/L006847/1, BBSRC-Meiogenix IPA grant BB/N007557/1, ERC ‘SynthHotSpot’ Consolidator Grant, National Natural Science Foundation of China grant 61403318, EMBO long-term postdoctoral fellowship ALT 807-2009, RDA Next- Generation BioGreen 21 Program PJ01337001, NRF Basic Science Research Program NRF- 2017R1D1AB03028374, the Bettencourt Schueller Foundation and a Gatsby Foundation Sainsbury studentship GAT3401. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.