Motivating Hotspots

摘要

An estimated 10 to 30% of fertilized human ova have more or fewer than the normal number of 46 chromosomes. Most cases of aneuploidy (that is, having an abnormal number of chromosomes) result from a reduced number of recombination events (less than one per chromosome arm) or an unusual placement of such events along the chromosome. Recombination between nonallelic copies can also lead to chromosomal rearrangements and deletions, many of which have been associated with disease. Despite its importance, much remains unknown about the process of recombination, especially for mammals. In particular, no sequences or chromosome structures that influence human recombination rates have been identified. On page 321 in this issue, Myers et al. present a fine-scale recombination map for the human genome and use it to identify the first set of candidate motifs.