Mutation patterns at dinucleotide microsatellite loci in humans.
Microsatellites are a major type of molecular markers in genetics studies. Their mutational dynamics are not clear. We investigated the patterns and characteristics of 97 mutation events unambiguously identified, from 53 multigenerational pedigrees with 630 subjects, at 362 autosomal dinucleotide microsatellite loci. A size-dependent mutation bias (in which long alleles are biased toward contraction, whereas short alleles are biased toward expansion) is observed. There is a statistically significant negative relationship between the magnitude (repeat numbers changed during mutation) and direction (contraction or expansion) of mutations and standardized allele size. Contrasting with earlier findings in humans, most mutation events (63%) in our study are multistep events that involve changes of more than one repeat unit. There was no correlation between mutation rate and recombination rate. Our data indicate that mutational dynamics at microsatellite loci are more complicated than the generalized stepwise mutation models.
Huang
Qing-Yang
QY
Osteoporosis Research Center and Department of Biomedical Sciences, Creighton University, Omaha, NE 68131, USA.
Xu
Fu-Hua
FH
Shen
Hui
H
Deng
Hong-Yi
HY
Liu
Yong-Jun
YJ
Liu
Yao-Zhong
YZ
Li
Jin-Long
JL
Recker
Robert R
RR
Deng
Hong-Wen
HW
D000483:Alleles; D015982:Bias; D002875:Chromosomes / Q000235:genetics; D004252:DNA Mutational Analysis; D018900:Dinucleotide Repeats / Q000235:genetics*; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D008957:Models, Genetic; D016296:Mutagenesis / Q000235:genetics*; D010375:Pedigree; D011995:Recombination, Genetic / Q000235:genetics