Meiotic crossover control: Interplay between the recombination process and chromosome organization

Meiosis exclusively occurs in the germ cells of eukaryotic organisms during sexual reproduction. A striking feature of this process is meiotic recombination, which results in the formation of DNA crossovers between the paternal and maternal chromosomes. Crossovers are pivotal in ensuring the accurate segregation of chromosomes during gamete formation, resulting in offspring that possess half of their progenitor's chromosome complement. Furthermore, crossovers play a crucial role in promoting genetic diversity within the offspring. The process of meiotic recombination is implemented in meiotic chromosomes by direct interaction between recombination complexes and the underlying loop/axis architecture of chromosomes. Consequently, CO patterning is subject to tight regulation by meiotic chromosome structures. Significant advances have been made in recent years in understanding the molecular mechanisms underlying these processes. We summarize the prevailing perspective on the organization of meiotic chromosomes, the meiotic recombination, with particular emphasis on CO patterning, and their interaction. We also provide a review of the current models for potential mechanisms for these processes.