Analysis on genetic polymorphism of 5 STR loci selected from X chromosome

Objective: To select short tandem repeats(STR) from X chromosome. Methods: STR is a universal genetic marker that has changeable polymorphism and stable heredity in human genome. It is a specific DNA segment composed of 2-6 base pairs as its core sequence. It is an ideal DNA marker used in linkage analysis and gene mapping. In this study, 8 short tandem repeats were selected from two genomic clones on X chromosome by using BCM Search Launcher. Primers amplifying the STR loci were designed by using Primer 3.0 according to the unique sequence flanking the STRs. Polymorphisms of the short tandem repeats in Chinese population were evaluated by PCR amplification and PAGE. Results: Five of these STRs were polymorphic. Chi-square test indicated that the distribution of genotypes agreed with Hardy-Weinberg equilibrium (P > 0.05). Conclusion: Five polymorphic short tandem repeats have been identified on chromosome X and will be useful for linkage analysis and gene mapping.