Characteristics and frequency of germline mutations at microsatellite loci from the human Y chromosome, as revealed by direct observation in father/son pairs.
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.
Kayser
M
M
Max-Planck-Institut für evolutionäre Anthropologie, D-04103 Leipzig, Germany. kayser@eva.mpg.de.
Roewer
L
L
Hedman
M
M
Henke
L
L
Henke
J
J
Brauer
S
S
Krüger
C
C
Krawczak
M
M
Nagy
M
M
Dobosz
T
T
Szibor
R
R
de Knijff
P
P
Stoneking
M
M
Sajantila
A
A
D000293:Adolescent; D000328:Adult; D000483:Alleles; D001483:Base Sequence; D019143:Evolution, Molecular; D005220:Fathers; D005787:Gene Frequency / Q000235:genetics*; D018095:Germ-Line Mutation / Q000235:genetics*; D006801:Humans; D007700:Kinetics; D008297:Male; D008540:Meiosis / Q000235:genetics; D018895:Microsatellite Repeats / Q000235:genetics*; D008957:Models, Genetic; D016296:Mutagenesis / Q000235:genetics; D009679:Nuclear Family; D010331:Paternal Age; D010334:Paternity; D011995:Recombination, Genetic / Q000235:genetics; D014998:Y Chromosome / Q000235:genetics*