Genetic polymorphisms of fifteen short tandem repeat loci in Chengdu Han population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To acquire the population genetic data of fifteen short tandem repeat (STR) loci in Chengdu Han population.</p><p><b>METHODS</b>A total of 210 EDTA-blood specimens were collected from the unrelated individuals in Chengdu Han population. The DNA samples were extracted with Chelex method and amplified by multiplex PCR technique. The PCR products were analyzed by an automatic genetic analyzer; the relative fragment's lengths of PCR products were calculated by gene scan analysis software and afterward genotyped by genotype software.</p><p><b>RESULTS</b>Fifteen STR loci of the 210 samples showed a successful result of genotyping. The heterozygosities of the fifteen STR loci in Chengdu Han population were found to be 0.529-0.881; the combined exclusion probability and discrimination power for the fifteen STR loci in Chengdu Han population were determined to be 0.999998 and 7.3 x 10 (-17); respectively.</p><p><b>CONCLUSION</b>The distinct genotype of fifteen STR loci and the sex of sample could be unveiled just through PCR and electrophoresis once, and a higher measured value could be obtained for both the combined discrimination power and the exclusion probability; the fifteen STR loci can meet the needs of the parentage testing and personal identification in forensic medicine.</p>

Study on the construction of standard D12S391 allelic ladder and its genetic polymorphism in six populations / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To resolve the problem of the accuracy and standardization of short tandem repeat-polymerase chain reaction (STR-PCR) typing in forensic practice, the authors have designed a new method of producing standard D12S391 allelic ladder.</p><p><b>METHODS</b>Nine different PCR amplified D12S391 allelic fragments were isolated from the gel, eluted into the distilled water and re-amplified by PCR. The purified allelic fragments were then blunt-end subcloned individually into the pUC plasmid vectors and transfected into competent E.coli DH5 alpha(TM) cells. The sequencing results confirmed that the size and the structure of the inserts were correct. The recombinant plasmids DNA with 9 inserts were then used as templates for PCR re-amplification to generate D12S391 standard ladder.</p><p><b>RESULTS</b>With the ladder, the authors studied the genetic polymorphisms of D12S391 locus in six populations (German, Japanese and Chinese south-western Han, northern Han, Weiwu'er and Hui populations), and the respective primary data in the six populations were obtained. D12S391 locus showed high polymorphism in all six populations, and its exclusion power and discrimination power are 0.609-0.786 and 0.940-0.952 respectively.</p><p><b>CONCLUSION</b>The results demonstrate that the standard ladder generated via this method is excellent, and D12S391 locus is robust for genetic research and forensic application.</p>

INVESTIGATION ON THE C_3 PHENOTYPE FREQUENCIES IN THE HAN POPULATION IN CHENGDU AREA AND C_3 PHENOTYPING IN HUMAN BLOOD STAINS USING CELLULOSE ACETATE ELECTROPHORESIS FOLLOWED BY IMMUNOFIXATION / 中国法医学杂志

The distribution of C_3 phenotype frequencies in the Han population in Cheng-du area was studied by means of cellulose acetate electrophoresis followed byimmunofixation.In 400 unrelated healthy individuals three C_3 phenotypes weredemonstrated.Their frequencies were as follows:SS=397,FS=2 and SSvar=1.Their gene frequencies were as follows:C_3~S=0.9963,C_3~F=0.0025 and C_3~(svar)=0.0013.The C_3 phenotype frequencies were in good agreement with those expec-ted.C_3 phenotyping in the huma bloodstains kept at 37℃ and room temp-lasserature for two days,at 4℃ for 23 days(cotton bloodstains)and for 35 days(g-bloodstains),and -20℃ for at least 87 days could be performed.C_3 ph-enotypingin human serum could be performed at roon temperature for 3 days,as 4℃ for 13days and at -20℃ for at least 106 days.C_3 phenotyping was usedin five casesof paternity dispute.