title: Evidence for heterozygote instability in microsatellite loci in house wrens.
abstract: Microsatellite loci have high mutation rates and high levels of allelic variation, but the factors influencing their mutation rate are not well understood. The proposal that heterozygosity may increase mutation rates has profound implications for understanding the evolution of microsatellite loci, but currently has limited empirical support. We examined 20 microsatellite mutations identified in an analysis of 12 260 meiotic events across three loci in two populations of a songbird, the house wren (Troglodytes aedon). We found that for an allele of a given length, mutation was significantly more likely when there was a relatively large difference in size between the allele and its homologue (i.e. a large 'allele span'). Our results support the proposal of heterozygote instability at microsatellite loci.
authors: Department of Biological Sciences, Towson University, Towson, MD 21252-0001, USA. bmasters@towson.edu
authors: Brian S
authors: BS
authors: Masters
authors: L Scott
authors: LS
authors: Johnson
authors: Bonnie G P
authors: BG
authors: Johnson
authors: Jessica L
authors: JL
authors: Brubaker
authors: Scott K
authors: SK
authors: Sakaluk
authors: Charles F
authors: CF
authors: Thompson
mesh_terms: D000818:Animals; D005260:Female; D005819:Genetic Markers; D006579:Heterozygote; D008297:Male; D053842:Microsatellite Instability; D020308:Songbirds / Q000235:genetics*
chemical_list: D005819:Genetic Markers