Preprint maps how PRDM9 allelic diversity shapes meiotic recombination landscapes in Atlantic salmon

A preprint posted to bioRxiv reports the first large-scale characterisation of how natural variation in the PRDM9 gene shapes meiotic recombination across the genome in Atlantic salmon (Salmo salar). The work, conducted using data from an aquaculture population, provides a detailed picture of how different PRDM9 alleles — distinguished by variation in the zinc-finger array that determines where the protein binds — direct crossovers to distinct genomic locations.

PRDM9 is the primary determinant of recombination hotspot locations in many vertebrate lineages, including humans and other mammals. Its role in salmonids was only recently established, making the Atlantic salmon an important model for understanding how PRDM9-directed recombination evolved outside the mammalian lineage.

The authors genotyped PRDM9 across a large number of individuals and integrated this with crossover data to demonstrate that allele-specific binding preferences translate into markedly different recombination landscapes — with implications for how genetic diversity is generated and maintained in salmonid populations. The extent of PRDM9 allelic diversity within the aquaculture cohort was found to be substantial.

The findings are relevant to population geneticists studying recombination biology, to researchers working on salmonid evolution and conservation, and to the aquaculture genetics community. This is a preprint and has not yet been peer-reviewed.