During meiosis, maternal and paternal chromosomes undergo exchanges by homologous recombination. This is essential for fertility and contributes to genome evolution. In many eukaryotes, sites of meiotic recombination, also called hotspots, are regions of accessible chromatin, but in many vertebrates, their location follows a distinct pattern and is specified by PR domain-containing protein 9 (PRDM9). The control of the recombination landscape by PRDM9 has many implications in terms of the molecular mechanisms underlying the interaction between homologues during meiotic prophase and genetic diversity. My project seeks to explore molecular mechanisms in genetic recombination rate and meiotic dysregulation using mouse hybrids.