Characteristics and Frequency of Germline Mutations at Microsatellite Loci From the Human Y Chromosome, as Revealed by Direct Observation in father/son Pairs

Am J Hum Genet. 2000 May;66(5):1580-8. doi: 10.1086/302905. Epub 2000 Apr 6.

Abstract

A number of applications of analysis of human Y-chromosome microsatellite loci to human evolution and forensic science require reliable estimates of the mutation rate and knowledge of the mutational mechanism. We therefore screened a total of 4,999 meioses from father/son pairs with confirmed paternity (probability >/=99. 9%) at 15 Y-chromosomal microsatellite loci and identified 14 mutations. The locus-specific mutation-rate estimates were 0-8. 58x10-3, and the average mutation rate estimates were 3.17x10-3 (95% confidence interval [CI] 1.89-4.94x10-3) across 8 tetranucleotide microsatellites and 2.80x10-3 (95% CI 1.72-4.27x10-3) across all 15 Y-chromosomal microsatellites studied. Our data show a mutational bias toward length increase, on the basis of observation of more repeat gains than losses (10:4). The data are in almost complete agreement with the stepwise-mutation model, with 13 single-repeat changes and 1 double-repeat change. Sequence analysis revealed that all mutations occurred in uninterrupted homogenous arrays of >/=11 repeats. We conclude that mutation rates and characteristics of human Y-chromosomal microsatellites are consistent with those of autosomal microsatellites. This indicates that the general mutational mechanism of microsatellites is independent of recombination.

MeSH terms

  • Adolescent
  • Adult
  • Alleles
  • Base Sequence
  • Evolution, Molecular
  • Fathers*
  • Gene Frequency / genetics*
  • Germ-Line Mutation / genetics*
  • Humans
  • Kinetics
  • Male
  • Meiosis / genetics
  • Microsatellite Repeats / genetics*
  • Models, Genetic
  • Mutagenesis / genetics
  • Nuclear Family*
  • Paternal Age
  • Paternity
  • Recombination, Genetic / genetics
  • Y Chromosome / genetics*