Conserved features of recombination control in vertebrates

Abstract

A recent study in PLOS Biology on the epigenetic recombination regulator PRDM9 in salmonid fish reveals that its function has been preserved across vertebrates for hundreds of millions of years, with rapidly evolving DNA-binding domains being a defining attribute.

Fig 1. Functional PRDM9 in salmonids has 4 hallmark features.

(A) (I) Recombination hotspots that share common motifs, (II) rapid evolution and high variability in its DNA binding domain, (III) a double positive epigenetic H3K4 and H3K36 trimethylation signal, (IV) positional variation in hotspots between populations. PRDM9-independent recombination occurs at promoters with characteristic H3K4 trimethylation, and the positions of hotspots show evolutionary stability. (B) As the distinctive characteristics of PRDM9 were previously only known to exist in mammals, the results of Raynaud and colleagues thereby move the evolutionary origin of the dynamic hotspot placement by the PRDM9 protein to an earlier time than previously believed, indicated by an arrow connecting the dashed lines in a phylogenetic tree of representative species, where PRDM9 losses identified by [4] are indicated by stars. Created in BioRender. ODENTHAL-HESSE, L. (2024) https://BioRender.com/l11h793.