Human chromosome Y-specific short tandem repeat (Y-specific STR) markers have useful properties for forensic applications. However, there is a need to develop more Y-specific STR markers because the discriminating power of each STR locus is limited. In the present study, we describe our results on two new Y-specific STR markers, which were initially reported by White et al. [Genomics 57 (1999) 433] as Y-GATA-C4 and Y-GATA-A10. The distributions of alleles and haplotypes for both Y-specific STR loci were studied in a Chinese Han population sample. Allele determination was carried out by comparison with sequenced allelic ladders which were made inhouse. Following the recommendations of the International Society of Forensic Genetics, the allele classification for both Y-specific STR loci was based on the number of repeat motifs. The results show that the haplotype diversity, the power of discrimination and the exclusion probability in the Chinese population for both Y-specific STR loci were 0.9090. The implication from this study is that Y-GATA-C4 and Y-GATA-A10 are useful Y-specific STR markers for forensic DNA typing in Chinese populations.

Institute of Forensic Medicine, west China University of MedicaI scIences, 610044 chengdu, PR Institute of Forensic Medicine, University of Cologne, 50823 KOin, FRG Since its introduction in 1985, VNTR polymorphism analysis has rapidly become a routine technique for forensic biology and population genetics But sO far there ore stlll some controversies surrounding VNTR polymorphisms. one of them being whether they violate the assumptions of Hardy-Weinberg equilibrium (HWE). Conceming biostotical tests the only significant dfiference between VNTR loci analysed by AMp-FLP and tradifionaI serological markers is that there are more alleles at a particular VNTR locus. so that not all genotypes can be observed in a relatively sinail sample Therefore. some indireat methods have been suggested to test HWE forthese VNTR Ioci (1-4), but the efficiency ofthem was not evaluated. our Purpose here is to Compare the efficiency of dfiferent statisticaI tests and to suggest a more sensitive new modification

Pentanucleotide tandem repeat markers are interesting for forensic sciences, because they may present less stutter on the electrophoretic pattern We focused on the anaysis of the DNA sequence for each allele at the pentanucleotide STR locus D10S2325 in order to understand their structm-es in the buman genome and to construct human allelic ladder, which is necessary for forensic DNA typing. In orderto evaluate the forensic applicability of Dl0S2325 and to construct a preliminary database, the genotype distributions and allele frequencies in three major ethnic groups were investigated The population saillples included Caucasians (Gemlans), Africans (African Americans), and Asians (Chinese). A total of 520 samples from unrelated individuals was analyzed by Amp-FLp. An example of each allele and new alleles were sequenced Anele determination was carried out by comparison with a sequenced human allelic ladder made in-house. This pentanucleotide STR provided easily interpretable results. A total of 15 alleles was found in our population samples ThTee new alleles were observed and named as alleles 19 and 21 based on the number of repeat motifs, While allele 19 can be divided furdier into two alleles. 19a and 19 according to analysis 0f the sequence No evidence of deviation from Hardy-Weinberg equilibfimn was observed in 64 confimled father/motber/child triplets no mutation event was observed. Using a maximmn likelihood method. the mutation rate was indirectly esthnated as 2.5

Pentanucleotide tandem repeat markers are of interest for forensic science because they may present less stutter in electrophoretic patterns. We focused on the analysis of the DNA sequence for each allele at two pentanucleotide STR loci, D6S957 and D10S2325, in order to understand their structures in the human genome and to construct allelic ladders, necessary for forensic DNA typing. In order to evaluate the forensic applicability of both pentanucleotide tandem repeat loci and to construct a preliminary database, the genotype distributions and allele frequencies in different ethnic groups were investigated. The population samples included Caucasians (Germans) and Asians (Chinese). The Amp-FLP technique was employed for DNA typing. An example of each allele and new alleles were sequenced. Allele determination for each pentanucleotide STR locus was carried out by comparison with a sequenced allelic ladder made in-house. Both pentanucleotide STR markers provided easily interpretable results. No evidence of deviation from Hardy-Weinberg equilibrium was observed. In 64 confirmed father/mother/child trios, no mutation event was observed. Using a maximum likelihood method, the mutation rate at both STR loci was indirectly estimated as 2.5 10