Interhomolog polymorphism shapes meiotic crossover within the Arabidopsis RAC1 and RPP13 disease resistance genes.
Public Library of Science (PLoS)
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Serra, H., Choi, K., Zhao, X., Blackwell, A. R., Kim, J., & Henderson, I. (2018). Interhomolog polymorphism shapes meiotic crossover within the Arabidopsis RAC1 and RPP13 disease resistance genes.. PLoS genetics, 14 (12), e1007843. https://doi.org/10.1371/journal.pgen.1007843
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.
Chromosomes, Plant, Chromatin, Plants, Genetically Modified, Arabidopsis, Arabidopsis Proteins, Meiosis, Plant Diseases, Crossing Over, Genetic, Mutation, Polymorphism, Genetic, Genes, Plant, DNA Breaks, Double-Stranded, High-Throughput Nucleotide Sequencing, Disease Resistance, Homologous Recombination
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.
Royal Society (uf0762030)
Isaac Newton Trust (1026(ab))
Gatsby Charitable Foundation (GAT2962)
Royal Society (uf120133)
Gatsby Charitable Foundation (GAT3401)
ECH2020 EUROPEAN RESEARCH COUNCIL (ERC) (681987)
External DOI: https://doi.org/10.1371/journal.pgen.1007843
This record's URL: https://www.repository.cam.ac.uk/handle/1810/287499
Attribution 4.0 International
Licence URL: https://creativecommons.org/licenses/by/4.0/