Distinctive genetic signatures of Alu/STR compound systems revealed by analyses of Mediterranean and Middle East populations

Abstract

The Middle East and Mediterranean represents one of the most ancient and largest areas of human civilization. Although several genetic studies have been carried out on certain regions of this area, it would be interesting to take advantage of additional global studies, including larger numbers of regions. In this paper we aim to expand previous genetic studies on populations from this area by investigating new populations and providing a global view based on the distribution of CD4 and FXIIIB Alu/STR (short tandem-repeat) compound systems. Haplotype frequencies of these two systems are determined in 352 DNA samples from Libya, Bahrain, and southern Iran. Comparative analyses and MDS plot representation show an evident genetic differentiation among the three population groups studied, i.e. North and South Mediterranean and Middle East. In addition, they assert the genetic richness and differentiation of Libya from other North African populations. Three haplotypes, CD4 90(+), FXIIIB 180(−) and CD4 110(−), were determined to be specific to Middle Eastern populations. The distribution of the two Alu/STR system haplotypes suggests that population movements between the North Mediterranean and Middle East are relatively less important than those involving the South Mediterranean with both the North Mediterranean and Middle East. However, the impact of these population movements is minimal compared to the long-standing settlement of the three population groups that have retained their genetic identity. Anthropological data thus obtained from the use of CD4 and FXIIIB Alu/STR compound systems would reflect the effect of advantages peculiar to these two systems. The determination of their haplotypes in more populations from the Middle East (particularly from the Arabian Peninsula) and from East Asia will provide more details on human evolutionary history.