A global analysis of Y-chromosomal haplotype diversity for 23 STR loci

In a worldwide collaborative effort, 19,630 Y-chromosomes were sampled from 129 different populations in 51 countries. These chromosomes were typed for 23 short-tandem repeat (STR) loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385ab, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, GATAH4, DYS481, DYS533, DYS549, DYS570, DYS576, and DYS643) and using the PowerPlex Y23 System (PPY23, Promega Corporation, Madison, WI). Locus-specific allelic spectra of these markers were determined and a consistently high level of allelic diversity was observed. A considerable number of null, duplicate and off-ladder alleles were revealed. Standard single-locus and haplotype-based parameters were calculated and compared between subsets of Y-STR markers established for forensic casework. The PPY23 marker set provides substantially stronger discriminatory power than other available kits but at the same time reveals the same general patterns of population structure as other marker sets. A strong correlation was observed between the number of Y-STRs included in a marker set and some of the forensic parameters under study. Interestingly a weak but consistent trend toward smaller genetic distances resulting from larger numbers of markers became apparent.Peer reviewe

Riboprinting and 16S rRNA Gene Sequencing for Identification of Brewery Pediococcus Isolates

A total of 46 brewery and 15 ATCC Pediococcus isolates were ribotyped using a Qualicon RiboPrinter. Of these, 41 isolates were identified as Pediococcus damnosus using EcoRI digestion. Three ATCC reference strains had patterns similar to each other and matched 17 of the brewery isolates. Six other brewing isolates were similar to ATCC 25249. The other 18 P. damnosus brewery isolates had unique patterns. Of the remaining brewing isolates, one was identified as P. parvulus, two were identified as P. acidilactici, and two were identified as unique Pediococcus species. The use of alternate restriction endonucleases indicated that PstI and PvuII could further differentiate some strains having identical EcoRI profiles. An acid-resistant P. damnosus isolate could be distinguished from non-acid-resistant varieties of the same species using PstI instead of EcoRI. 16S rRNA gene sequence analysis was compared to riboprinting for identifying pediococci. The complete 16S rRNA gene was PCR amplified and sequenced from seven brewery isolates and three ATCC references with distinctive riboprint patterns. The 16S rRNA gene sequences from six different brewery P. damnosus isolates were homologous with a high degree of similarity to the GenBank reference strain but were identical to each other and one ATCC strain with the exception of 1 bp in one strain. A slime-producing, beer spoilage isolate had 16S rRNA gene sequence homology to the P. acidilactici reference strain, in agreement with the riboprint data. Although 16S rRNA gene sequencing correctly identified the genus and species of the test Pediococcus isolates, riboprinting proved to be a better method for subspecies differentiation