SEQUENCING OF SPO11-1-OLIGONUCLEOTIDES IN H2A.Z DEPOSITION MUTANT IN ARABIDOPSIS

Abstract

Meiotic recombination is initiated by a widely conserved SPO11 transesterase-mediated DSBs. The meiotic DSB landscapes vary among species and depend on either specific DNA sequence or chromatin structure. By sequencing Arabidopsis SPO11-1-oligonucleitides we found that meiotic DSB frequency and distribution are quantitatively correlated with chromatin accessibility. Consistently, DNA methylation and H3K9 dimthylation inhibit meiotic DSB formation around hetetochromatic pericentromeres and centromeres. However, how chromatin remodeling factors including SWR1-complex influence the meiotic DSBs remain elusive in Arabidopsis. We mapped a high-profile DSB landscape in arp6 mutant, defective in H2A.Z deposition. The ATP-dependent SWR1 chromatin remodeling shapes meiotic DSB pattern around gene promoters and terminators. Our results provide an insight into how meiotic recombination initiation is finely controlled by SWR1 chromatin remodeling complex.