High-resolution mapping of crossovers in human sperm defines a minisatellite-associated recombination hotspot.

Little is known about the fine-scale distribution of meiotic crossovers in human chromosomes. Methods have therefore been developed for detecting and mapping recombination products directly in human sperm DNA. Analysis of crossovers adjacent to the GC-rich minisatellite MS32, which is known to mutate by conversion and crossover within the repeat array, revealed an intense and highly localized recombination hotspot centered upstream of the locus and extending into the beginning of the minisatellite. Allele-specific cosuppression of crossovers and repeat instability suggests that the hotspot is responsible for driving repeat turnover at MS32 and thus that minisatellites might evolve as by-products of localized meiotic recombination in the human genome.