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

Human chromosome Y-specific short tandein repeat (Y-specific STR) markers have useful properties for forensic appplications However, there is a need to develop more Y-specific STR markers, because the discriminating power of each STR locus is liinited In the present study, we describe our results on six new Y-specific STR markers that were initially located using sequence database infomlation by Ayub et al and were named DYS434, DYS435, DYS436, DYS437. DYS438 and DYS439. Our stndies focused on the analysis of the DNA sequence for each allele at all six Y-specific STR loci in order to mlderstand their structures in the human genome and to construct human allelic ladders. which are necessary for forensic DNA typing in addition. the haplotype distribution for all six analyzed loci was studied in a Chinese Han population sample The results indicate that DYS434. DYS435, DYS436. DYS437, DYS438 and DYS439 are useful Y-specific STR markers for forensic sciences.

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