The landscape of mouse meiotic double-strand break formation, processing and repair

SPO11 generates hundreds of DNA double-strand breaks (DSBs) to initiate meiotic recombination. Heritability and genome stability are shaped by the nonrandom distribution of DSBs, but mechanisms molding this landscape remain poorly understood. Here we exploit genome-wide maps of mouse DSBs at unprecedented nucleotide resolution to uncover previously invisible spatial features of recombination. At fine scale, we reveal a stereotyped hotspot structure––DSBs occur within narrow zones between methylated nucleosomes––and identify relationships between SPO11, chromatin, and the histone methyltransferase PRDM9. At large scale, DSB formation is suppressed on non-homologous portions of the sex chromosomes via the DSB-responsive kinase ATM, which also shapes the autosomal DSB landscape at multiple size scales. We also provide the first genome-wide analysis of exonucleolytic DSB resection lengths and elucidate spatial relationships between DSBs and recombination products. Our results paint a comprehensive picture of features that govern successive steps in mammalian meiotic recombination. Overall design: Five samples total: SPO11-oligo maps from C57BL/6J (one map), Atm+/+ (one map), Atm+/– (map), and Atm–/– (two biological replicate maps) mice