Repeated losses of PRDM9-directed recombination despite the conservation of PRDM9 across vertebrates
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.
Xiphophorus birchmanni and Xiphophorus malinche RNAseq data Raw sequence readsPublicly available at the NCBI BioProject (accession no: PRJNA358086).
Article and author information
National Institutes of Health (R01 GM83098)
- Molly Przeworski
National Science Foundation (DDIG DEB-1405232)
- Molly Schumer
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Animal experimentation: Animals used for this study were handled according to the approved institutional animal care and use committee (IACUC) protocol AUP# - IACUC 2013-0168 of Texas A&M University. All individuals used for dissections were first treated with MS-222 for anesthesia to minimize suffering before being euthanized.
- Bernard de Massy, Institute of Human Genetics, CNRS UPR 1142, France
- Received: December 10, 2016
- Accepted: June 3, 2017
- Accepted Manuscript published: June 6, 2017 (version 1)
- Version of Record published: July 20, 2017 (version 2)
© 2017, Baker et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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- Genetics and Genomics
The ways in which recombination sites are determined during meiosis are becoming clearer following a phylogenomic analysis for 225 different species.
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