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.

Relevant for various areas of human genetics, Y-chromosomal short tandem repeats (Y-STRs) are commonly used for testing close paternal relationships among individuals and populations, and for male lineage identification. However, even the widely used 17-loci Yfiler set cannot resolve individuals and populations completely. Here, 52 centers generated quality-controlled data of 13 rapidly mutating (RM) Y-STRs in 14,644 related and unrelated males from 111 worldwide populations. Strikingly, >99% of the 12,272 unrelated males were completely individualized. Haplotype diversity was extremely high (global: 0.9999985, regional: 0.99836–0.9999988). Haplotype sharing between populations was almost absent except for six (0.05%) of the 12,156 haplotypes. Haplotype sharing within populations was generally rare (0.8% nonunique haplotypes), significantly lower in urban (0.9%) than rural (2.1%) and highest in endogamous groups (14.3%). Analysis of molecular variance revealed 99.98% of variation within populations, 0.018% among populations within groups, and 0.002% among groups. Of the 2,372 newly and 156 previously typed male relative pairs, 29% were differentiated including 27% of the 2,378 father–son pairs. Relative to Yfiler, haplotype diversity was increased in 86% of the populations tested and overall male relative differentiation was raised by 23.5%. Our study demonstrates the value of RM Y-STRs in identifying and separating unrelated and related males and provides a reference database.

China has repeatedly been the subject of genetic studies to elucidate its prehistoric and historic demography. While some studies reported a genetic distinction between Northern and Southern Han Chinese, others showed a more clinal picture of small differences within China. Here, we investigated the distribution of Y chromosome variation along administrative as well as ethnic divisions in the mainland territory of the People's Republic of China, including 28 administrative regions and 19 recognized Chinese nationalities, to assess the impact of recent demographic processes. To this end, we analyzed 37,994 Y chromosomal 17-marker haplotype profiles from the YHRD database with respect to forensic diversity measures and genetic distance between groups defined by administrative boundaries and ethnic origin. We observed high diversity throughout all Chinese provinces and ethnicities. Some ethnicities, including most prominently Kazakhs and Tibetans, showed significant genetic differentiation from the Han and other groups. However, differences between provinces were, except for those located on the Tibetan plateau, less pronounced. This discrepancy is explicable by the sizeable presence of Han speakers, who showed high genetic homogeneity all across China, in nearly all studied provinces. Furthermore, we observed a continuous genetic North-South gradient in the Han, confirming previous reports of a clinal distribution of Y chromosome variation and being in notable concordance with the previously observed spatial distribution of autosomal variation. Our findings shed light on the demographic changes in China accrued by a fast-growing and increasingly mobile population.

Objectives: The Hui people are the adherents of Muslim faith and distributing throughout China.There are two contrasting hypotheses about the origin and diversification of the Hui people, namely, the demic diffusion involving the mass movement of people or simple cultural diffusion. Materials and methods:We collected 621 unrelated male individuals from 23 Hui populations all over China. We comprehensively genotyped more than 100 informative Y-chromosomal single nucleotide polymorphisms and 17 Y-chromosomal short tandem repeats (STRs) on those samples.Results: Co-analyzed with published worldwide populations, our results suggest the origin of Hui people has involved massive assimilation of indigenous East Asians with about 70% in total of the paternal ancestry could be traced back to East Asia and the left 30% to various regions in West Eurasia.Discussion: The genetic structure of the extant Hui populations was primarily shaped by the indigenous East Asian populations as they contribute the majority part of the paternal lineages of Hui people. The West Eurasian admixture was probably a sex-biased male-driven process since we have not found such a high proportion of West Eurasian gene flow on autosomal STRs and maternal mtDNA.

Microhaplotypes are an emerging type of forensic genetic marker that are expected to support multiple forensic applications. Here, we developed a 124-plex panel for microhaplotype genotyping based on next-generation sequencing (NGS). The panel yielded intralocus and interlocus balanced sequencing data with a high percentage of effective reads. A full genotype was determined with as little as 0.1 ng of input DNA. Parallel mixture experiments and in-depth comparative analyses were performed with capillary-electrophoresis-based short tandem repeat (STR) and NGS-based microhaplotype genotyping, and demonstrated that microhaplotypes are far superior to STRs for mixture deconvolution. DNA from Han Chinese individuals (n = 256) was sequenced with the 124-plex panel. In total, 514 alleles were observed, and the forensic genetic parameters were calculated. A comparison of the forensic parameters for the 20 microhaplotypes with the top A e values in the 124-plex panel and 20 commonly used forensic STRs showed that these microhaplotypes were as effective as STRs in identifying individuals. A linkage disequilibrium analysis showed that 106 of the 124 microhaplotypes were independently hereditary, and the combined match probability for these 106 microhaplotypes was 5.23 × 10 −66. We conclude that this 124-plex microhaplotype panel is a powerful tool for forensic applications. The microhaplotype is a powerful new type of forensic genetic marker 1,2. It is the combination of two or more closely linked single-nucleotide polymorphisms (SNPs) within DNA segments of 200 base pairs (bp), and offers multiple forensic applications 3-7. Short tandem repeat (STR) genotyping is currently the dominant technology in forensic DNA laboratories. Although it works well with single-sourced DNA samples, great challenges are encountered with DNA mixtures because stutters in the major donor DNA can be indistinguishable from alleles in the minor donor DNA 3,8. Stutters are unavoidable during the replication of repetitive DNA, and they severely interfere with mixture deconvolution. SNPs are not repetitive sequences, but are typically biallelic, which restricts their utility in the analysis of mixtures. Microhaplotypes have the advantages of both STRs and SNPs because they are multiallelic and do not produce stutters during amplification. Therefore, microhaplotypes are perfect genetic markers for mixture deconvolution. Although capillary electrophoresis (CE)-based genetic analyzers are widely used in forensic DNA laboratories, these machines are unsuitable for microhaplotype genotyping 8. Several methods have been used for microhaplotype detection. TaqMan assays have been used to type each SNP that constitutes a microhaplotype 8 , followed by a PHASE software analysis to determine the cis/trans relationships between individual SNP alleles. Single-strand conformational polymorphisms 9 and high-resolution melting curves 4 have also been used for microhaplotype genotyping. These methods are simple and inexpensive, but they can pose problems when multipl...