Short tandem repeats (STRs) are highly polymorphic sequences and have been extensively used as genetic markers in mapping studies, disease diagnosis, and human identity testing. In this study, 11 STR markers on chromosome 21, including D21S1432, D21S11, D21S1246, D21S1412, D21S1437, D21S1442, D21S2039, D21S1270, D21S1435, D21S1409, and D21S1446, were analyzed in 740 unrelated Han individuals from southeast China. A total of 132 alleles, ranging from 7-21 for each locus, were named according to the guidelines of the International Society for Forensic Haemogenetics.
Short tandem repeats
Recombination patterns can be indirectly inferred by means of linkage disequilibrium (LD) estimates, since LD is negatively correlated with genetic distance. However, LD does not necessarily have absolute correspondence with genetic distance. We estimated LD at 5 loci located in the 21q22.3 region. These STRs (D21S1440, D21S168, D21S1260, D21S1446, and D21S1411) covered 8.81 Mb of the 21q22.3 region. They were genotyped by conventional PCR. Similar size samples previously validated by sequencing were used as a genotyping control.
There have been numerous studies genetically characterizing Old World Primates using microsatellites. However, few studies have been made of New World species and none on free-ranging Cebus apella, even though it is probably the most widely distributed species of monkey in the New World. The paucity of studies is due, in part, to the lack of polymorphisms described for this species.