Y-STR markers from Ladakh in the Himalayas.

A total of 223 samples from the general population of Ladakh in Northwestern India were amplified at 17 Y-STR loci using the AmpFlSTR® Yfiler™ system. The DNA profiles generated were employed to generate allelic frequencies, gene diversity, haplotype diversity and discrimination capacity values as well as number of different haplotypes, fraction of unique haplotypes and Rst pair wise genetic distances. Multidimensional Scaling (MDS) and Correspondence Analysis (CA) were performed with the Rst values and allelic frequencies, respectively. The 17-loci discrimination capacity of Ladakh was found to be 0.8093. Eleven out of the 16 loci have diversity values greater than 0.6, and 13 loci possess values greater than 0.5. Ladakh exhibits no significant genetic difference to seven of the 15 reference forensic databases after Bonferroni correction, three of which are located in South Central Asian and four are from the Himalayan region. Rst genetic distance values before and after Bonferroni corrections illustrate the capacity of the Yfiler system to discriminate among Himalayan populations. The intermediate position of the Ladakh population in the MDS and CA plots likely reflects genetic flow and admixture with neighboring populations. In addition, the longitudinal partition of populations in the MDS and CA plots likely reflect human dispersals such as the silk road migrations.

On the Bantu expansion.

Here we report the results of fine resolution Y chromosomal analyses (Y-SNP and Y-STR) of 267 Bantu-speaking males from three populations located in the southeast region of Africa. In an effort to determine the relative Y chromosomal affinities of these three genotyped populations, the findings are interpreted in the context of 74 geographically and ethnically targeted African reference populations representing four major ethno-linguistic groups (Afro-Asiatic, Niger Kordofanin, Khoisan and Pygmoid). In this investigation, we detected a general similarity in the Y chromosome lineages among the geographically dispersed Bantu-speaking populations suggesting a shared heritage and the shallow time depth of the Bantu Expansion. Also, micro-variations in the Bantu Y chromosomal composition across the continent highlight location-specific gene flow patterns with non-Bantu-speaking populations (Khoisan, Pygmy, Afro-Asiatic). Our Y chromosomal results also indicate that the three Bantu-speaking Southeast populations genotyped exhibit unique gene flow patterns involving Eurasian populations but fail to reveal a prevailing genetic affinity to East or Central African Bantu-speaking groups. In addition, the Y-SNP data underscores a longitudinal partitioning in sub-Sahara Africa of two R1b1 subgroups, R1b1-P25* (west) and R1b1a2-M269 (east). No evidence was observed linking the B2a haplogroup detected in the genotyped Southeast African Bantu-speaking populations to gene flow from contemporary Khoisan groups.

Mayans: a Y chromosome perspective.

UNLABELLED: In spite of the wealth of available cultural and archeological information as well as general interest in the Mayans, little is known about their genetics. In this study, for the first time, we attempt to alleviate this lacuna of knowledge by comprehensively investigating the Y chromosome composition of contemporary Mayan populations throughout their domain. To accomplish this, five geographically targeted and ethnically distinct Mayan populations are investigated using Y-SNP and Y-STR markers. FINDINGS: overall, the Mayan populations as a group are highly homogeneous, basically made up of only two autochthonous haplogroups, Q1a2a1a1*-M3 and Q1a2a1*-L54. Although the Y-STR data illustrates diversity, this diversity, for the most part, is uniformly distributed among geographically distant Mayan populations. Similar haplotypes among populations, abundance of singletons and absence of population partitioning within networks among Mayan populations suggest recent population expansion and substantial gene flow within the Mayan dominion, possibly due to the development of agriculture, the establishment of interacting City-State systems and commerce.

Ladakh, India: the land of high passes and genetic heterogeneity reveals a confluence of migrations.

Owing to its geographic location near the longitudinal center of Asia, Ladakh, the land of high passes, has witnessed numerous demographic movements during the past millenniums of occupation. In an effort to view Ladakh's multicultural history from a paternal genetic perspective, we performed a high-resolution Y-chromosomal survey of Ladakh, within the context of Y haplogroup and haplotype distributions of 41 Asian reference populations. The results of this investigation highlight the rich ethnic and genetic diversity of Ladkah which includes genetic contributions from disparate regions of the continent including, West, East, South and Central Asia. The phylogenetic signals from Ladakh are consistent with the Indo-Aryans' occupation during the Neolithic age and its historic connection with Tibet, as well as the East-West gene flow associated with the Silk Road.

Phylogenetic and forensic studies of the Southeast Florida Hispanic population using the next-generation forensic PowerPlex® Y23 STR marker system.

The purpose of this study is to examine the robustness and sensitivity of the newly available Y-STR multiplex kit, the PowerPlex® Y23 System, by comparing our data at the 23-loci level to the routinely used 17 loci provided by the AmpFlSTR® Yfiler® PCR Amplification kit. For the first time, allelic and genotypic frequencies for the 23 Y-STR loci included in the PowerPlex® Y23 System are provided for the Southeast Florida Hispanic (SFH) population. In addition, we have characterized the SFH population in terms of intra-population and inter-population parameters. We also compared these indices of forensic and population genetics interest in the SFH population to comparable data of previously published populations to assess their phylogenetic relationships. Our 23-loci data was shown to provide more discriminatory values as compared to the data when using only 17 loci. Also, the RST distance values demonstrate the superior capacity of the PowerPlex® Y23 system to discriminate among populations.