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

A panel of Y-specific STR loci, including DYS19, DYS389, DYS390, DYS391, DYS392, and DYS393 was analyzed using horizontal nondenaturing polyacrylamide gel electrophoresis with a discontinuous buffer system (horizontal disk-PAGE). In order to obtain correct results for the larger DYS389 and DYS392 alleles, it was necessary to design new primers that bind closer to the repeat region and lead to a significant reduction of the amplified fragment size. Using the modified primer sets the horizontal disk-PAGE results were consistent with a nondenaturing approach using fluorescent primers and a 377 automated sequencer. The modified procedure also amplifies the second repeat stretch at the duplicated DYS389 locus as a single fragment, which results in an immediate allele identification. The results indicate that horizontal disk-PAGE with silverstaining is a simple approach to type the recommended Y-specific STR markers.

In order to evaluate the forensic applicability of the STR locus D20S161 and construct a preliminary database, the genotype distributions and allele frequencies in five populations from three main ethnic groups were investigated, including Germans, Slovakians, African Americans, Japanese and Chinese. A total of 512 samples from unrelated individuals and 85 confirmed father/mother/ child triplets were analyzed by PCR and allele determination was carried out by comparison with a sequenced human allelic ladder. The results showed that D20S161 typing was both precise and reliable. A total of 7 alleles was found in these populations and no evidence of deviation from Hardy-Weinberg equilibrium was observed. Pairwise comparisons between populations showed that there were significant differences in the distributions of the allele frequencies among the three main ethnic groups. No mutation events were observed from the confirmed father/mother/child triplets. With a maximum likelihood method, the mutation rate was indirectly estimated as 2.5 × 10–5. These results suggest that D20S161 is a useful marker for forensic casework and paternity analysis.

The purpose of our work was to establish a method for analysis of Y-SNP based on the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The results of our study implied that the analysis of Y-SNP was proved to be suitable for forensic application and provided new genetic markers for the forensic purpose. D 2005 Published by Elsevier B.V.