GSE203309
DNA polymerase epsilon interacts with SUVH2/9 to mediate meiotic DSB associated gene silencing beyond DNA methylation in Arabidopsis [RNA-seq]
Meiotic recombination is initiated from the SPORULATION 11 (SPO11)-triggered formation of double strand breaks (DSBs) that usually occur in open chromatin with active transcriptional features in many eukaryotes. However, gene transcription at meiotic DSB sites appears to be detrimental for repair, and the mechanisms for gene silencing at DSB sites are largely undefined, especially in plants. Here, we demonstrate that the largest DNA polymerase epsilon subunit POL2A interacts with SU(VAR)3-9 homologs SUVH2 and SUVH9. N-SIM (Structured Illumination Microscopy) observation shows that the colocalization of SUVH2 with meiotic DSB marker ?- H2AX is dependent on POL2A. RNA-seq of male meiocytes identifies that POL2A and SUVH2 jointly repress the expression of 865 genes, which have several known characteristics associated with meiotic DSB sites. Bisulfite-seq and small RNA-seq of male meiocytes support the idea that the silencing of these genes by POL2A and SUVH2/9 is likely independent of CHH methylation or 24-nt siRNA accumulation. Consequently, pol2a suvh2 suvh9 triple mutants have more severe defects in meiotic recombination and fertility compared with either pol2a or suvh2 suvh9. Taken together, our results not only identify a new epigenetic regulatory mechanism for gene silencing in male meiocytes, but also reveal new roles for DNA polymerase and SUVH2/9 beyond their classic functions in mitosis. Overall design: Examination of gene expression in meiocytes and seedlings of mutants, such as pol2a-1, suvh2 suvh9 etc, and wild type plants