A Whole-Chromosome Analysis of Meiotic Recombination in Drosophila melanogaster

G3: Genes, Genomes, Genetics

Kendra N. Walton⁴  Justin P. Blumenstiel¹  R. Scott Hawley²  Satomi Takeo⁴  William D. Gilliland³  Ariel Paulson⁴  Karen K. Staehling⁴  Hua Li⁴  Danny E. Miller⁴  Kavyasree Nandanan⁴  Madelaine M. Gogol⁴  Aaron C. Noll⁴  Anoja G. Perera⁴ 

[1] Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045;Stowers Institute for Medical Research, Kansas City, MO 64110Department of Physiology, Kansas University Medical Center, Kansas City, KS 66160Stowers Institute for Medical Research, Kansas City, MO 64110Stowers Institute for Medical Research, Kansas City, MO 64110Department of Physiology, Kansas University Medical Center, Kansas City, KS 66160Department of Physiology, Kansas University Medical Center, Kansas City, KS 66160Stowers Institute for Medical Research, Kansas City, MO 64110Department of Physiology, Kansas University Medical Center, Kansas City, KS 66160;Department of Biology, Depaul University, Chicago, IL 60604Department of Biology, Depaul University, Chicago, IL 60604Department of Biology, Depaul University, Chicago, IL 60604;Stowers Institute for Medical Research, Kansas City, MO 64110Stowers Institute for Medical Research, Kansas City, MO 64110Stowers Institute for Medical Research, Kansas City, MO 64110

关键词: crossing over;    gene conversion;    double-strand break;    genome sequencing;    meiosis;   

DOI  :  10.1534/g3.111.001396

学科分类：生物科学（综合）

来源: Genetics Society of America

【 摘 要 】

Although traditional genetic assays have characterized the pattern of crossing over across the genome in Drosophila melanogaster, these assays could not precisely define the location of crossovers. Even less is known about the frequency and distribution of noncrossover gene conversion events. To assess the specific number and positions of both meiotic gene conversion and crossover events, we sequenced the genomes of male progeny from females heterozygous for 93,538 X chromosomal single-nucleotide and InDel polymorphisms. From the analysis of the 30 F1 hemizygous X chromosomes, we detected 15 crossover and 5 noncrossover gene conversion events. Taking into account the nonuniform distribution of polymorphism along the chromosome arm, we estimate that most oocytes experience 1 crossover event and 1.6 gene conversion events per X chromosome pair per meiosis. An extrapolation to the entire genome would predict approximately 5 crossover events and 8.6 conversion events per meiosis. Mean gene conversion tract lengths were estimated to be 476 base pairs, yielding a per nucleotide conversion rate of 0.86 × 10^−5 per meiosis. Both of these values are consistent with estimates of conversion frequency and tract length obtained from studies of rosy, the only gene for which gene conversion has been studied extensively in Drosophila. Motif-enrichment analysis revealed a GTGGAAA motif that was enriched near crossovers but not near gene conversions. The low-complexity and frequent occurrence of this motif may in part explain why, in contrast to mammalian systems, no meiotic crossover hotspots have been found in Drosophila.

【 授权许可】

Unknown