GT repeats are associated with recombination on human chromosome 22

The rate of meiotic recombination not a constant function of physical dista nce across chromosomes. This variation is manifested by recombination hot s pots and cold spots, observed in ail organisms ranging From bacteria to hum ans. It is generally believed that factors such as primary and secondary DN A sequence, as well as chromatin structure and associated proteins, influen ce the frequency of recombination within a specific region. Several such fa ctors, for example repetitive sequences, gene promoters, or regions with th e ability to adopt Z-DNA conformation, have been hypothesized to enhance re combination. However, apart from specific examples, no general trends of as sociation between recombination rates and particular DNA sequence motifs ha ve been reported. In this paper, we analyze the complete sequence data from human chromosome 22 and compare microstellite repeat distributions with mi totic recombination patterns available from earlier genetic studies. We sho w significant correlation between long tandem GT repeats, which are known t o form Z-DNA and interact with several components of the recombination mach inery, and recombination hot spots on human chromosome 22.