Mol Phylogenet Evol. 2003 Sep;28(3):458-72. Related Articles, Links

Y-chromosome and mtDNA polymorphisms in Iraq, a crossroad of the early human dispersal and of post-Neolithic migrations.

Al-Zahery N, Semino O, Benuzzi G, Magri C, Passarino G, Torroni A, Santachiara-Benerecetti AS.

Dipartimento di Genetica e Microbiologia A. Buzzati Traverso, Universita di Pavia, Via Ferrata, 1, 27100 Pavia, Italy.

Analyses of mtDNA and Y-chromosome variation were performed in a sample of Iraqis, a scarcely investigated population of the "Fertile Crescent." A total of 216 mtDNAs were screened for the diagnostic RFLP markers of the main Eurasian and African haplogroups. A subset of these samples, whose HVS-I sequences were previously obtained, was also examined by high-resolution restriction analysis. The Y-chromosome variation was investigated in 139 subjects by using 17 biallelic markers and the 49a,f/Taq I system. For both uniparental systems, the large majority of the haplogroups observed in the Iraqi population are those (H, J, T, and U for the mtDNA, and J(xM172) and J-M172 for the Y chromosome) considered to have originated in the Middle East and to have later spread all over Western Eurasia. However, about 9% of the mtDNAs and 30% of the Y-chromosomes most likely represent arrivals from distant geographic regions. The different proportion of long-range genetic input observed for the mtDNA and the Y chromosome appears to indicate that events of gene flow to this area might have involved mainly males rather than females.