5
Saudi Arabian Y-Chromosome diversity and its relationship with nearby regions
Khaled K Abu-Amero1*, Ali Hellani2, Ana M González3, Jose M Larruga3, Vicente M Cabrera3 published 22 September 2009
http://www.biomedcentral.com/1471-2156/10/59
"Saudi Arabia differentiates from other Arabian Peninsula countries by a higher presence of J2-M172 lineages. It is significantly different from Yemen mainly due to a comparative reduction of sub-Saharan Africa E1-M123 and Levantine J1-M267 male lineages. Around 14% of the Saudi Arabia Y-chromosome pool is typical of African biogeographic ancestry, 17% arrived to the area from the East across Iran, while the remainder 69% could be considered of direct or indirect Levantine ascription. Interestingly, basal E-M96* (n = 2) and J-M304* (n = 3) lineages have been detected, for the first time, in the Arabian Peninsula. Coalescence time for the most prominent J1-M267 haplogroup in Saudi Arabia (11.6 ± 1.9 ky) is similar to that obtained previously for Yemen (11.3 ± 2) but significantly older that those estimated for Qatar (7.3 ± 1.8) and UAE (6.8 ± 1.5). "
"In the first analysis, congruently with its pair-wise distances, Somalia appears as an outlier, and the close relationship found between Qatar and Yemen is also reflected in the plot. For the rest of the Arabian samples a clear partition exists, whereas Oman and UAE appear closer to the Levant samples that include Egypt, the Saudi component positions approximates towards the northeast edge of the Near East. However, the population spatial distribution along to the first and second principal components in the PC analysis is quite different."
"As the Y-chromosome phylogeography is well structured [30,31], it is possible to roughly quantify the different male inputs from surrounding regions into Arabia. When haplogroups A, B, E-M96, E1-P2, E1-M2, and E1-M35 frequencies are assumed to be representative of the Africa contribution and frequencies of C, F, G, H, L, O, Q and R1-M17 as arrivals, across Iran, from Central, southern, and southeastern Asia, inputs of 13.4% and 16.6% from both areas are estimated for Saudi Arabia. UAE is the region with the least African (5.5%) and the greatest Iranian influence (36.8%). If the global inputs for the Arabian Peninsula are estimated to approximate 10% from sub-Saharan Africa and 22% from Iran, the remaining 68% could be considered of direct or indirect Levantine ascription. "
Consistent with the rest of the Arabian Peninsula, haplogroup J is the most abundant component in Saudi Arabia embracing 58% of its Y-chromosomes. Its two main subclades (J1-M267 and J2-M172), show opposite latitudinal gradients in the Middle East. J1-M267 is more abundant in the southern areas, reaching a frequency around 73% in Yemen, whereas J2-M172 is more common in the Levant. Most probably, the significant higher presence of J2-M172 in Saudi compared to other Arabian populations is due to the larger northern boundary that Saudi Arabia shares with the Levant. The Fertile Crescent region has been considered the most probable origin of the earliest dispersions of both subclades [21,32,33]. Further subdivisions of J1-M172 have uncovered more recent Bronze age expansions from Turkey and the Balkans traced by the J2-M67/M92 and J2-M12 subgroups [21,34,35].
Curiously, the Iranian female flow (18%) was also rather similar to that calculated for Africa. Although a slight ratio excess of Sub-Saharan African female versus male gene flow is detected (1.12) we do not found the strong sexual bias proposed by other authors for Arabian populations and attributed to the peculiarities of the recent slave-trade [12,36]. Without dismissing the role mediated by slavery, the geographical distribution of these sub-Saharan African lineages in the Arabian Peninsula seems to indicate a prehistoric entrance of a noticeable portion of these lineages that participated in the building of the primitive Arabian population [8,9].
In conclusion, the Y-chromosome genetic structure of the Arabian Peninsula seems to be mainly modulated by geography. The data confirm that this area has mainly been a recipient of gene flow from its African and Asian surrounding areas, probably mainly since the last Glacial maximum onwards. Although rare deep rooting lineages for Y chromosome haplogroups E and J have been detected, the presence of more basal clades supportive of the southern exit route of modern humans to Eurasian, were not found.
Reply With Quote
Originally Posted by randomguy1235
Saudi Arabia
Japan
United Kingdom
Bookmarks