Japanese Emperors: Y-DNA Haplogroup D1b1a2 Nov 22, 2018 18:17:53 GMT
Post by Admin on Nov 22, 2018 18:17:53 GMT
Koreans are generally considered a Northeast Asian group, thought to be related to Altaic-language-speaking populations. However, recent findings have indicated that the peopling of Korea might have been more complex, involving dual origins from both southern and northern parts of East Asia. To understand the male lineage history of Korea, more data from informative genetic markers from Korea and its surrounding regions are necessary. In this study, 25 Y-chromosome single nucleotide polymorphism markers and 17 Y-chromosome short tandem repeat (Y-STR) loci were genotyped in 1,108 males from several populations in East Asia.
In general, we found East Asian populations to be characterized by male haplogroup homogeneity, showing major Y-chromosomal expansions of haplogroup O-M175 lineages. Interestingly, a high frequency (31.4%) of haplogroup O2b-SRY465 (and its sublineage) is characteristic of male Koreans, whereas the haplogroup distribution elsewhere in East Asian populations is patchy. The ages of the haplogroup O2b-SRY465 lineages (~9,900 years) and the pattern of variation within the lineages suggested an ancient origin in a nearby part of northeastern Asia, followed by an expansion in the vicinity of the Korean Peninsula. In addition, the coalescence time (~4,400 years) for the age of haplogroup O2b1-47z, and its Y-STR diversity, suggest that this lineage probably originated in Korea. Further studies with sufficiently large sample sizes to cover the vast East Asian region and using genomewide genotyping should provide further insights.
These findings are consistent with linguistic, archaeological and historical evidence, which suggest that the direct ancestors of Koreans were proto-Koreans who inhabited the northeastern region of China and the Korean Peninsula during the Neolithic (8,000-1,000 BC) and Bronze (1,500-400 BC) Ages.
Technitially all the samples were analyzed for 12 Y-SNP markers (M9, M45, M89, M119, M122, M174, M175, M214, P31, SRY465, 47z and RPS4Y) using a previously described protocol . The samples belonging to haplogroups C, D, K, NO, O3 and P were subjected to further typing with an additional 13 Y-SNP markers to designate the subclades: two three-plex, three two-plex and one single-plex SNaPshot assay were developed for these 13 Y-SNP markers (Figure 1). The nomenclature of the haplogroups followed that of the Y Chromosome Consortium . Primers for PCR and single-base extension (SBE) reactions were designed (Primer 3.0 program; frodo.wi.mit.edu/primer3/, Cambridge, MA, USA) (see Additional file 1, Table S1; see Additional file 2, Table S2). Conditions of the SNaPshot assays were the same as those previously described , with the exception of PCR purification; in our assay, the PCR products were purified by adding 2 μl of an exonuclease I-shrimp alkaline phosphatase preparation (Exo-SAP; USB Corp., Cleveland, OH, USA) to 5 μl PCR product.
Distribution of Y chromosome haplogroup frequencies in the East Asian populations studied