1. Genetic recombination is directed away from functional genomic elements in mice
- Author
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Brick, Kevin, Smagulova, Fatima, Khil, Pavel, Camerini-Otero, R. Daniel, and Petukhova, Galina V.
- Subjects
Meiosis ,Genetic research ,Methyltransferases -- Properties ,Genetic recombination -- Research ,Environmental issues ,Science and technology ,Zoology and wildlife conservation - Abstract
Genetic recombination occurs during meiosis, the key developmental programme of gametogenesis. Recombination in mammals has been recently linked to the activity of a histone H3 methyltransferase, PR domain containing 9 (PRDM9) (1-6), the product of the only known speciation-associated gene in mammals (7). PRDM9 is thought to determine the preferred recombination sites--recombination hotspots--through sequence-specific binding of its highly polymorphic multi-Zn-finger domain (8). Nevertheless, Prdm9 knockout mice are proficient at initiating recombination (9). Here we map and analyse the genome-wide distribution of recombination initiation sites in Prdm9 knockout mice and in two mouse strains with different Prdm9 alleles and their [F.sub.1] hybrid. We show that PRDM9 determines the positions of practically all hotspots in the mouse genome, with the exception of the pseudo-autosomal region (PAR)--the only area of the genome that undergoes recombination in 100% of cells (10). Surprisingly, hotspots are still observed in Prdm9 knockout mice, and as in wild type, these hotspots are found at H3 lysine 4 (H3K4) trimethylation marks. However, in the absence of PRDM9, most recombination is initiated at promoters and at other sites of PRDM9-independent H3K4 trimethylation. Such sites are rarely targeted in wild-type mice, indicating an unexpected role of the PRDM9 protein in sequestering the recombination machinery away from gene-promoter regions and other functional genomic elements., Homologous recombination is initiated by the introduction of DNA double-stranded breaks (DSBs) by the SPO11 protein (11), and we have previously shown that recombination sites can be mapped by sequencing [...]
- Published
- 2012
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