R. Deka et al., POPULATION-GENETICS OF DINUCLEOTIDE (DC-DA)(N)CENTER-DOT(DG-DT)(N) POLYMORPHISMS IN WORLD POPULATIONS, American journal of human genetics, 56(2), 1995, pp. 461-474
We have characterized eight dinucleotide (dC-dA)(n).(dG-dT)(n) repeat
loci located on human chromosome 13q in eight human populations and in
a sample of chimpanzees. Even though there is substantial variation i
n allele frequencies at each locus, at a given locus the most frequent
alleles are shared by all human populations. The level of heterozygos
ity is reduced in isolated or small populations, such as the Pehuenche
Indians of Chile, the Dogrib of Canada, and the New Guinea highlander
s. On the other hand, larger average heterozygosities are observed in
large and cosmopolitan populations, such as the Sokoto population from
Nigeria and German Caucasians. Conformity with Hardy-Weinberg equilib
rium is generally observed at these loci, unless (a) a population is i
solated or small or (b) the repeat motif of the locus is not perfect (
e.g., D13S197). Multilocus genotype probabilities at these microsatell
ite loci do not show departure from the independence rule, unless the
loci are closely linked. The allele size distributions at these (CA)(n
) loci do not follow a strict single-step stepwise-mutation model. How
ever, this feature does not compromise the ability to detect populatio
n affinities, when these loci are used simultaneously. The microsatell
ite loci examined here are present and, with the exception of the locu
s D13S197, are polymorphic in the chimpanzees, showing an overlapping
distribution of allele sizes with those observed in human populations.