Finally!! – Rym Kefi(2014) – Origin of mtDNA H Sept 26, 2014 13:20:25 GMT -5
Post by djoser-xyyman on Sept 26, 2014 13:20:25 GMT -5
Phylogeny and genetic structure of Tunisian populations and their position within Mediterranean - Rym Kefi 2014
Compared to 4206 mtDNA sequences from Mediterranean populations, 354 different sequences were observed in Tunisia, among them 234 WERE UNIQUE. The distribution of unique sequences is higher in the North of Tunisia (number of unique sequences (N139), than in the South (N86). The highest value is observed in Capital Tunis (N36). These values were corrected by the number of individuals in each sample and results from this study showed that among Mediterranean populations, significantly Tunisia (10.2%) contain the highest frequency of unique sequences. On the second position we found populations from Galicia (GAL, 3.4%), Northern Greece (GNG, 3.3%), Alexandria (ALX, 2.8%) and Turkey (TUR, 2.2%). Thirdly, frequencies of unique sequences in populations from Greece (GRE), Italia (SIC, ITS), Spain (AND, CAT), Egypt (EGY) and Palestine (PAL) ranged from 1–2%, while the remaining Mediterranean populations contains values of unique sequences under the level of 1% (Figure 2).
Genetic structure of the Tunisian population
The analysis of the genetic diversity of the Tunisian population and the dispersal distribution of haplogroup frequencies were summarized in (Table 3, Figure 1, Supplementary material Appendices A, C, D). The mtDNA genetic pool of Tunisian populations contains three components: Eurasian lineages (H, HV, U (excepted U6), T, J, V, K, N, R, U5, I, W, X), Sub-Saharan lineages (L0, L1, L2, L3) and North African lineages (U6 and M1). The exception was observed in two Southern Berber populations from Jerba and Chenini-Douiret where the North African component was absent. The Eurasian lineages are predominant in all Tunisian populations, with the exception of the Southern Berbers from Bou Saaˆd where the percentage of the Eurasian lineages was equivalent to the percentage of the Sub-Saharan lineages (43% and 44% respectively). The Eurasian lineages range from 43% in the population of Bou Saaˆd to 87% IN BERBERS FROM JERBA.
Phylogeny of Tunisian with Mediterranean populations
The FST matrix relating the 61 Mediterranean populations including the 16 Tunisian populations was reported in Supplementary material Appendices G, H. Comparison of FST values from pairs of populations revealed that most Tunisian samples displayed significant differences with European populations. The highest FST values (0.38271) were observed between Chenini-Douiret from Southern Tunisia and Galicia from Iberian Peninsula. The phenogram based on the resulting FST matrix (Figure 5A) displayed three clusters. The first (I) was composed by six Tunisian populations with different ethnic origins clustered with populations from Libya, Morocco and Egypt. The second group was composed by seven Tunisian populations with different ethnic origins clustered with populations from Algeria Morocco and Egypt. The third group was mainly composed by European and Near Eastern populations. Only one Tunisian population from Jerba Berbers (JEB) belonged to the third group. According to the phenogram (Figure 5A) and MDS plots (Figure 5B), populations
of Chenini-Douiret and Bou Saaˆd from Tunisia, Mozabites from Algeria and Fazzan Al Awaynat from Libya were outliers. IN ORDER TO REFINE THE POSITION OF TUNISIANS WITHIN MEDITERRANEAN POPULATIONS we pooled all Tunisian populations into one group (TUN), with the exception of the outliers CHO and SAB. Statistical analyses are shown in Supplementary material Appendices I, J. Phylogenetic and MDS analysis showed that Tunisians occupied central position in the NJ tree and the MDS plots (Figures 6, 7) between North Africans and Near Eastern populations. According to the matrix of significance, Tunisians are significantly distant from the majority of European populations EXCEPT POPULATIONS FROM SARDINIA, CORSICA, TUSCANY AND SOME SPANISH POPULATIONS (VAL, BAS, MIN, CHU).
The present phylogenetic study and the AMOVA analysis deduced that there are no differences between the three ethnic Tunisian groups: Arabs, Berbers and Andalusians. In fact, in the phenogram and the MDS plots, one cluster could contain populations from different ethnic groups and there is no specific cluster for one ethnic group (Figure 4). This means that the previous ethnic studies using uniparental markers (mtDNA and Y chromosome) (Cherni et al., 2005, 2009; Ennafaa et al., 2011; Loueslati et al., 2006) and autosomal markers (Ancestry Informative SNP panel) (Khodjet-el-Khil et al., 2011).