RT Journal Article SR Electronic T1 Non-crossover gene conversions show strong GC bias and unexpected clustering in humans JF bioRxiv FD Cold Spring Harbor Laboratory SP 009175 DO 10.1101/009175 A1 Amy L. Williams A1 Giulio Genovese A1 Thomas Dyer A1 Katherine Truax A1 Goo Jun A1 Nick Patterson A1 Joanne E. Curran A1 Ravi Duggirala A1 John Blangero A1 David Reich A1 Molly Przeworski A1 T2D-GENES Consortium YR 2014 UL http://biorxiv.org/content/early/2014/09/18/009175.abstract AB Although the past decade has seen tremendous progress in our understanding of fine-scale recombination, little is known about non-crossover (or “gene conversion”) resolutions. We report the first genome-wide study of non-crossover gene conversion events in humans. Using SNP array data from 94 meioses, we identified 107 sites affected by non-crossover events, of which 51/53 were confirmed in sequence data. Our results suggest that a site is involved in a non-crossover event at a rate of 6.7×10−6/bp/generation, consistent with results from sperm-typing studies. Observed non-crossover events show strong allelic bias, with 70% (61–79%) of events transmitting GC alleles (P=7.9×10−5), and have tracts lengths that vary over more than an order of magnitude. Strikingly, in 4 of 15 regions with available resequencing data, multiple (∼2–4) distinct non-crossover events cluster within ∼20–30 kb. This pattern has not been reported previously in mammals and is inconsistent with canonical models of double strand break repair.