Shojiro Tsukamoto

Short Tandem Repeat Polymorphism of the D2S1242 Locus in a Japanese Population

Allele frequencies and sequence characteristics of the D2S1242 short tandem repeat (STR) locus were studied in a Japanese population sample. A total of 10 D2S1242 alleles and 34 genotypes were identified in 273 unrelated Japanese individuals. The five most common alleles detected had frequencies of over 10%. No deviations from Hardy-Weinberg equilibrium were found when the expected allele values were compared with the observed values. Sequence analysis of each allele showed a tetranucleotide polymorphism. Alleles 9 to 14 had different sequence structures than alleles 15 to 19. Allele 18 had a different sequence in the Japanese sample compared to an Austrian sample. The power of discrimination was 0.95. The present results demonstrate that the D2S1242 STR locus is a useful genetic marker in the Japanese population.

Frequency of D1S80 and HLA DQα alleles in a Chinese population

Allele frequency distributions for the D1S80 (MCT118) and HLA DQα loci were determined in a Chinese population sample using the polymerase chain reaction (PCR). A total of 25 alleles and 100 phenotypes were observed for D 1 S80. The frequency of allele 18 was higher than allele 24 only in this Chinese population when compared to other reported populations. A total of 6 alleles and 21 possible phenotypes were observed for HLA DQα. The power of discrimination was 0.97 and 0.93 for D1S80 and HLA DQα, respectively.

DNA typing of the D1S80 locus using capillary zone electrophoresis

DNA typing of the D1S80 locus was carried out using capillary polyacrylamide gel zone electrophoresis (CZE). The D1S80 allelic ladder was isolated within 40 min in polyacrylamide gel columns of 50 μm inner diameter and 30 cm length. The PCR products and ladder marker in the injection port were electrophoresed and detected by UV absorption (254 nm). The typing was determined according to migration of DNA fragments on the electropherograms, which permits simultaneous analysis of both the test sample polymerase chain reaction products and the ladder marker. The two-step sample injection method applied in this study allows us to use minute amounts of the ladder maker. This procedure provides a reliable, economical and rapid method for D1S80 typing.