Influences of array size and homogeneity on minisatellite mutation

摘要: Unstable minisatellites display high frequencies of spontaneous gain and loss repeats in the human germline. Most length changes arise through complex recombination events including intra-allelic duplications/deletions inter-allelic transfers repeats. Definition factors modulating instability requires both measurement mutation rate detailed analysis mutant structures at level individual alleles. We have measured rates sperm for a wide range alleles highly unstable minisatellite CEB1. Instability varies by three orders magnitude between increases steadily with size tandem array. Structural molecules derived from six revealed that it is rearrangements which array duplication tend to cluster within homogeneous segments alleles; phenomena resemble features trinucleotide repeat instability. In contrast, occur fairly constant rate, irrespective length, show mild polarity towards one end minisatellite, suggesting possible influence flanking DNA on these conversion-like events.