Repository logo
 

Epigenetic activation of meiotic recombination near Arabidopsis thaliana centromeres via loss of H3K9me2 and non-CG DNA methylation.

Published version
Peer-reviewed

Type

Article

Change log

Authors

Underwood, Charles J 
Choi, Kyuha 
Lambing, Christophe 
Serra, Heïdi 

Abstract

Eukaryotic centromeres contain the kinetochore, which connects chromosomes to the spindle allowing segregation. During meiosis, centromeres are suppressed for inter-homolog crossover, as recombination in these regions can cause chromosome missegregation and aneuploidy. Plant centromeres are surrounded by transposon-dense pericentromeric heterochromatin that is epigenetically silenced by histone 3 lysine 9 dimethylation (H3K9me2), and DNA methylation in CG and non-CG sequence contexts. However, the role of these chromatin modifications in control of meiotic recombination in the pericentromeres is not fully understood. Here, we show that disruption of Arabidopsis thaliana H3K9me2 and non-CG DNA methylation pathways, for example, via mutation of the H3K9 methyltransferase genes KYP/SUVH4 SUVH5 SUVH6, or the CHG DNA methyltransferase gene CMT3, increases meiotic recombination in proximity to the centromeres. Using immunocytological detection of MLH1 foci and genotyping by sequencing of recombinant plants, we observe that H3K9me2 and non-CG DNA methylation pathway mutants show increased pericentromeric crossovers. Increased pericentromeric recombination in H3K9me2/non-CG mutants occurs in hybrid and inbred backgrounds and likely involves contributions from both the interfering and noninterfering crossover repair pathways. We also show that meiotic DNA double-strand breaks (DSBs) increase in H3K9me2/non-CG mutants within the pericentromeres, via purification and sequencing of SPO11-1-oligonucleotides. Therefore, H3K9me2 and non-CG DNA methylation exert a repressive effect on both meiotic DSB and crossover formation in plant pericentromeric heterochromatin. Our results may account for selection of enhancer trap Dissociation (Ds) transposons into the CMT3 gene by recombination with proximal transposon launch-pads.

Description

Keywords

Arabidopsis, Arabidopsis Proteins, Centromere, DNA (Cytosine-5-)-Methyltransferases, DNA Breaks, Double-Stranded, DNA Methylation, Epigenesis, Genetic, Genome, Plant, Heterochromatin, Histone-Lysine N-Methyltransferase, Histones, Homologous Recombination, Meiosis, Methyltransferases

Journal Title

Genome Res

Conference Name

Journal ISSN

1088-9051
1549-5469

Volume Title

28

Publisher

Cold Spring Harbor Laboratory
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)
Biotechnology and Biological Sciences Research Council (BB/N007557/1)
European Research Council (681987)