Here, we report the variation of 486 Y-chromosomes within the Ashkenazi and non-Ashkenazi Levite R1a clade, other Ashkenazi Jewish paternal lineages, as well as non-Levite Jewish and non-Jewish R1a samples.
Ashkenazi Jews appeared in Europe in the 10th century, and their ancestry is thought to comprise European (EU) and Middle-Eastern (ME) components… The inferred admixture time was ≈30 generations ago, but multiple lines of evidence suggest that it represents an average over two or more events, pre- and post-dating the founder event experienced by AJ in late medieval times. The time of the pre-bottleneck admixture event, which was likely Southern European, was estimated to ≈25–50 generations ago.
We analyzed 47 fully sequenced Y-chromosomes and reconstructed the haplogroup Q3 phylogenetic tree in detail. Haplogroup Q3-L275, derived from the oldest known split within Eurasian/American haplogroup Q, most likely occurred in West or Central Asia in the Upper Paleolithic period. During the Mesolithic and Neolithic epochs, Q3 remained a minor component of the West Asian Y-chromosome pool and gave rise to five branches (Q3a to Q3e), which spread across West, Central and parts of South Asia. Around 3–4 millennia ago (Bronze Age), the Q3a branch underwent a rapid expansion, splitting into seven branches, some of which entered Europe. One of these branches, Q3a1, was acquired by a population ancestral to Ashkenazi Jews and grew within this population during the 1st millennium AD, reaching up to 5% in present day Ashkenazi.
To investigate European introgression into Ashkenazi Jewry, the European-dominant haplogroup H mitochondrial DNA was examined. The results provided genetic evidence that gene flow between Jewish and non-Jewish populations occurred early in Jewish settlement in Europe with isolation of the groups thereafter.
We report on two of the oldest mitochondrial DNA clusters in existence with Jewish affiliation. Both are in haplogroup T2e1. Four unrelated individuals from the Mexico mtDNA project were found to have the control region mutations that characterize a Sephardic signature previously reported (motif 16114T-16192T within T2e). Full genomic sequencing found the identical coding region mutations as Sephardic individuals which provides genetic evidence for founders of Northern Mexico that were both female and Sephardic Jewish.
The relative roles of natural selection and accentuated genetic drift as explanations for the high frequency of more than 20 Ashkenazi Jewish disease alleles remain controversial. To test for the effects of a maternal bottleneck on the Ashkenazi Jewish population, we performed an extensive analysis of mitochondrial DNA (mtDNA) hypervariable segment 1 (HVS-1) sequence and restriction site polymorph
Genetic differences between the Samaritans and neighboring Jewish and non-Jewish populations are corroborated in the present study of 7,280 bp of nonrecombining Y-chromosome and 5,622 bp of coding and hypervariable segment I (HVS-I) mitochondrial DNA (mtDNA) sequences. Comparative sequence analysis was carried out on 12 Samaritan Y-chromosome, and mtDNA samples from nine male and seven female Samaritans separated by at least two generations. In addition, 1820 male individuals were analyzed, each representing Ethiopian, Ashkenazi, Iraqi, Libyan, Moroccan, and Yemenite Jews, as well as Druze and Palestinians, all currently living in Israel.