The y chromosome pool of Jews as part of the genetic landscape of the Middle East

A sample of 526 Y chromosomes representing six Middle Eastern populations ( Ashkenazi, Sephardic, and Kurdish Jews from Israel; Muslim Kurds; Muslim Ar abs from Israel and the Palestinian Authority Area; and Bedouin from the Ne gev) was analyzed for 13 binary polymorphisms and six microsatellite loci. The investigation of the genetic relationship among three Jewish communitie s revealed that Kurdish and Sephardic Jews were indistinguishable from one another, whereas both differed slightly, yet significantly, from Ashkenazi Jews. The differences among Ashkenazim may be a result of low-level gene fl ow from European populations and/or genetic drift during isolation. Admixtu re between Kurdish Jews and their former Muslim host population in Kurdista n appeared to be negligible. In comparison with data available from other r elevant populations in the region, Jews were found to be more closely relat ed to groups in the north of the Fertile Crescent (Kurds, Turks, and Armeni ans) than to their Arab neighbors. The two haplogroups Eu 9 and Eu 10 const itute a major part of the Y chromosome pool in the analyzed sample. Our dat a suggest that Eu 9 originated in the northern part, and Eu 10 in the south ern part of the Fertile Crescent. Genetic dating yielded estimates of the e xpansion of both haplogroups that cover the Neolithic period in the region. Palestinian Arabs and Bedouin differed from the other Middle Eastern popul ations studied here, mainly in specific high-frequency Eu 10 haplotypes not found in the non-Arab groups. These chromosomes might have been introduced through migrations from the Arabian Peninsula during the last two millenni a. The present study contributes to the elucidation of the complex demograp hic history that shaped the present-day genetic landscape in the region.