Genetic Polymorphisms Of12X Chromosome STR Loci In Guangxi Maonan Population

Objective: To investigate the genetic polymorphism of12short tandemrepeat(STR) loci on the X chromosome （DXS7133, DXS8378, DXS981,DXS7424, DXS6789, DXS10159, GATA165B12, DXS101, DXS7423,GATA31E08, DXS10164and DXS10162）of maonan groups in GuangxiProvince. Choose allele frequency in this groups with different groups in Chinato calculate the genetic distance between each other, and discussion therelationship between these groups in a preliminary.Methods:(1) Samples collection: Venous blood sample was collected from117unrelated healthy individuals more than three generations (55females,62males) in Guangxi huanjiang maonan ethnic groups, put2ml of sample into5mlof anticoagulation tube with sodium citrate in it, and was storaged in refrigeratorfor later use.(2) Methods: Genomic DNA was extracted by Chelex-100mothodand the12X-chromosomal STR loci were amplified by using AGCU X12STRPCR amplification Kit, using AB3130gene analyzer to detect the PCR products, and the results are analysed by GeneMapper ID v3.2software.(3) Data analysis:Allelic frequencies, genotype frequencies and haplotype frequencies wereobtained by a direct calculation; Using online software （http://www.chrx-str.org） to calculate polymorphism information content, the Chi-squaretest was performed to test Hardy-Weinberg equilibrium for female genotypefrequency. Using Phylip3.69statistical software to calculate Nei’s geneticdistance between different groups, and based on the genetic distance withMEGA5.0software build Phylogeny tree (UPGMA method).Results:(1) The numbers of alleles in the12X-STR loci were4,5,10,7,9,6,5,11,3,7,8and6, respectively; the numbers of genotypes in the55femaleswere5,9,23,19,18,16,7,25,5,17,12and15, respectively. The genotypefrequencies in females were in accordance with Hardy-Weinberg equilibrium(P>0.05). A total of34haplotypes were detected in DXS10159，DXS10162andDXS10164loci，and28haplotypes were detected in DXS101and DXS7424loci.The haplotype diversity reached0.9714and0.9228, respectively. The combinedpower of discrimination (DP) was0.99999954in males and0.99999999infemales, and the combined mean exclusion chance (MEC) was0.99999798inthe trio cases and0.99986322in the duo cases.(2) Genetic distance andphylogeny tree analysis based on X-STR allele frequencies in genesis showedthat Guangxi maonan ethnic group share a close relationship with Zhejiang hanethnic and Weifang han ethnic, is0.0060and0.0211; and far from Inner Mongolia daur ethnic group, is0.2665.Conclusion: The12X-STR loci were highly polymorphic in Guangximaonan population and it is powerful for individual identification, paternitytesting and population genetics. Genetic distance and phylogenic tree showedthat Guangxi maonan ethnic group share a close relationship with Zhejiang hanethnic and Weifang han ethnic, and far from Inner Mongolia daur ethnic group.