Genetic crossovers – the exchange of DNA between pairs of chromosomes from each parent – play a crucial role in accurate chromosome segregation during meiotic cell division. However, the mechanisms underlying the formation of these crossovers in mammals are poorly understood. To provide further insight into this process, researchers led by Francesca Cole, Ph.D., used genetic dissection to map the frequency and distribution of crossover points in mouse models.
The researchers discovered two unique intermediate steps that occur prior to recombination. Additionally, they highlighted the DNA mismatch repair protein MLH3 as a pivotal structural component required to form the junctions involved in recombination. These findings help refine the current understanding of recombination in mammals, advancing knowledge of how genes are transferred during meiosis.