human imprinted chromosomal regions are historical hot-spots of recombination人类印染色体区域重组的历史热点.pdfVIP

Human Imprinted Chromosomal Regions Are Historical Hot-Spots of Recombination 1¤a 1 1¤b 2 3 1,4* Ionel Sandovici , Sacha Kassovska-Bratinova , Joe E. Vaughan , Rae Stewart , Mark Leppert , Carmen Sapienza 1 Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America, 2 College of Science and Technology, Temple University, Philadelphia, Pennsylvania, United States of America, 3 Eccles Institute of Human Genetics, and Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America, 4 Department of Pathology and Laboratory Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America Human recombination rates vary along the chromosomes as well as between the two sexes. There is growing evidence that epigenetic factors may have an important influence on recombination rates, as well as on crossover position. Using both public database analysis and wet-bench approaches, we revisited the relationship between increased rates of meiotic recombination and genome imprinting. We constructed metric linkage disequilibrium (LD) maps for all human chromosomal regions known to contain one or more imprinted genes. We show that imprinted regions contain significantly more LD units (LDU) and have significantly more haplotype blocks of smaller sizes than flanking nonimprinted regions. There is also an excess of hot-spots of recombination at imprinted regions, and this is likely to do with the presence of imprinted genes, per se. These findings indicate that imprinted chromosomal regions are historical ‘‘hot-spots’’ of recombination. We