PT - JOURNAL ARTICLE AU - Baker, Zachary AU - Schumer, Molly AU - Haba, Yuki AU - Bashkirova, Lisa AU - Holland, Chris AU - Rosenthal, Gil G. AU - Przeworski, Molly TI - Repeated losses of PRDM9-directed recombination despite the conservation of PRDM9 across vertebrates AID - 10.1101/093096 DP - 2017 Jan 01 TA - bioRxiv PG - 093096 4099 - http://biorxiv.org/content/early/2017/05/12/093096.short 4100 - http://biorxiv.org/content/early/2017/05/12/093096.full AB - Studies of highly diverged species have revealed two mechanisms by which meiotic recombination is directed to the genome—through PRDM9 binding or by targeting promoter-like features—that lead to dramatically different evolutionary dynamics of hotspots. Here, we identify PRDM9 orthologs from genome and transcriptome data in 225 species. We find the complete PRDM9 ortholog across distantly related vertebrates but, despite this broad conservation, infer a minimum of six partial and three complete losses. Strikingly, taxa carrying the complete ortholog of PRDM9 are precisely those with rapid evolution of its predicted binding affinity, suggesting that all domains are necessary for directing recombination. Indeed, as we show, swordtail fish carrying only a partial but conserved ortholog share recombination properties with PRDM9 knock-outs.