Preprint examines sex differences in fine-scale recombination patterns in species without PRDM9

In many animal species, meiotic recombination does not occur uniformly across the genome but is concentrated at discrete sites known as hotspots. In humans and many other mammals, the protein PRDM9 directs recombination to these locations. However, several lineages — including birds and domestic dogs — have independently lost PRDM9, and in these species hotspots instead cluster at CpG islands in gene promoter regions.

A new preprint posted to bioRxiv investigates fine-scale sex differences in recombination patterns in PRDM9-independent species. The phenomenon of sex-differing recombination rates, known as heterochiasmy, is documented across many organisms, but its fine-scale genomic basis in lineages lacking PRDM9 has remained poorly characterised.

The authors find that sex differences in recombination in PRDM9-independent species operate at a fine scale and are not merely a reflection of broad chromosomal rate differences. The work contributes to understanding how recombination hotspot biology differs between species and between sexes, with implications for population genetic inference, breeding studies, and the evolutionary dynamics of recombination itself.

The preprint has not yet been peer-reviewed. The work is of primary interest to evolutionary and population genetics researchers and to educators covering meiosis and recombination.