Phylogeny and genetic structure of Tunisians and their position within Mediterranean populations.
Tunisia is located at the crossroads of Europe, the Middle East and Sub-Saharan Africa. This position might lead to numerous waves of migrations, contributing to the current genetic landscape of Tunisians. In this study, we analyzed 815 mitochondrial DNA (mtDNA) sequences from Tunisia in order to characterize the mitochondrial DNA genetic structure of this region, to construct the processes for its composition and to compare it to other Mediterranean populations. To that end, additional 4206 mtDNA sequences were compiled from previous studies performed in African (1237), Near Eastern (231) and European (2738) populations. Both phylogenetic and statistical analyses were performed. This study confirmed the mosaic genetic structure of the Tunisian population with the predominance of the Eurasian lineages, followed by the Sub-Saharan and North African lineages. Among Tunisians, the highest haplogroup and haplotype diversity were observed in particular in the Capital Tunis. No significant differentiation was observed between both geographical (Northern versus Southern Tunisia) and different ethnic groups in Tunisia. Our results highlight the presence of outliers and most frequent unique sequences in Tunisia (10.2%) compared to 45 Mediterranean populations. Phylogenetic analysis showed that the majority of Tunisian localities were closer to North Africans and Near Eastern populations than to Europeans. The exception was found for Berbers from Jerba which are clustered with Sardinians and Valencians.
Biomedical Genomics and Oncogenetics Laboratory (LR 11 IPT 05), Institut Pasteur de Tunis, Université El Manar de Tunis , Tunis , Tunisia and.
Rym
R
Kefi
Sana
S
Hsouna
Nizar
N
Ben Halim
Khaled
K
Lasram
Lilia
L
Romdhane
Habib
H
Messai
Sonia
S
Abdelhak
D004272:DNA, Mitochondrial / Q000737:chemistry*; D005006:Ethnicity / Q000235:genetics*; D014644:Genetic Variation; D005828:Genetics, Population; D006239:Haplotypes; D063426:Human Migration; D006801:Humans; D019083:Mediterranean Region; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D014416:Tunisia
D004272:DNA, Mitochondrial
Mediterranean populations; mitochondrial DNA; multidimentional scaling; phylogenetic trees; unique sequences