Friday, November 08, 2013 — Poster Session III | |||
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10:00 a.m. – 12:00 p.m. |
FAES Academic Center (Upper-Level Terrace) |
NIDDK |
GEN-28 |
Meiotic recombination is initiated by the formation of programmed double-strand breaks (DSBs) that cluster in narrow regions called hotspots. PRDM9 is the primary determinant of the location of hotspots in mammals. Hotspots have been identified in the human genome using computational analysis of patterns of linkage disequilibrium (LD) in populations; however, this method only permits the evaluation of sex-averaged and population-averaged recombination rates. Here, we exploit a method developed by us to perform the first direct high-resolution genome-wide analysis of meiotic recombination initiation hotspots in human males. The location of DSBs for the most part agrees with the historical hotspots from LD maps. On the broad scale, the genome-wide distribution of DSBs resembles the distribution of male specific crossovers. Both crossovers and DSBs are more frequent in subtelomeric regions suggesting that crossovers follow the distribution of DSBs. Examination of two individuals with the same Prdm9 allele revealed differential usage of about 5% of hotspots. Whole genome sequencing determined that only about 40% of polymorphic hotspots could be explained by a SNP at a putative PRDM9 binding site implying that factors other than PRDM9 are modulating hotspot strength in humans.