PLOS Genetics paper asks why meiotic recombination concentrates in hotspots

A research team including Julien Joseph, Thomas Brazier, Marie Raynaud, Sylvain Glémin, Frédéric Baudat, Bernard de Massy, Nicolas Lartillot, and Laurent Duret has published a study in PLOS Genetics asking a deceptively fundamental question: why does meiotic recombination — the exchange of DNA between parental chromosomes during gamete formation — concentrate in discrete genomic regions called hotspots rather than being distributed uniformly across chromosomes?

The phenomenon has long been observed in eukaryotes including humans, where the protein PRDM9 directs double-strand break formation to specific motifs that then act as recombination hotspots. The concentration of crossovers at hotspots has implications for genetic diversity generation, genome stability, and fertility. Yet the evolutionary logic of this architecture is not fully resolved.

The paper, published on 19 May 2026, takes a theoretical and evolutionary approach to modelling why hotspot-concentrated recombination is maintained by natural selection despite the well-documented self-destructive dynamic in which hotspot alleles tend to be eroded by biased gene conversion — a phenomenon sometimes called the hotspot conversion paradox. Researchers, evolutionary geneticists, and students studying meiosis and genome evolution will find this a useful contribution to the long-running debate about the function and maintenance of recombination hotspots. The work is peer-reviewed and distinct from the PRDM9 spermatogenesis preprint published earlier in the recent cluster window.