Mitochondrial DNA transit between West Asia and North Africa inferred from U6 phylogeography - PubMed (original) (raw)

Mitochondrial DNA transit between West Asia and North Africa inferred from U6 phylogeography

Nicole Maca-Meyer et al. BMC Genet. 2003.

Abstract

Background: World-wide phylogeographic distribution of human complete mitochondrial DNA sequences suggested a West Asian origin for the autochthonous North African lineage U6. We report here a more detailed analysis of this lineage, unraveling successive expansions that affected not only Africa but neighboring regions such as the Near East, the Iberian Peninsula and the Canary Islands.

Results: Divergence times, geographic origin and expansions of the U6 mitochondrial DNA clade, have been deduced from the analysis of 14 complete U6 sequences, and 56 different haplotypes, characterized by hypervariable segment sequences and RFLPs.

Conclusions: The most probable origin of the proto-U6 lineage was the Near East. Around 30,000 years ago it spread to North Africa where it represents a signature of regional continuity. Subgroup U6a reflects the first African expansion from the Maghrib returning to the east in Paleolithic times. Derivative clade U6a1 signals a posterior movement from East Africa back to the Maghrib and the Near East. This migration coincides with the probable Afroasiatic linguistic expansion. U6b and U6c clades, restricted to West Africa, had more localized expansions. U6b probably reached the Iberian Peninsula during the Capsian diffusion in North Africa. Two autochthonous derivatives of these clades (U6b1 and U6c1) indicate the arrival of North African settlers to the Canarian Archipelago in prehistoric times, most probably due to the Saharan desiccation. The absence of these Canarian lineages nowadays in Africa suggests important demographic movements in the western area of this Continent.

PubMed Disclaimer

Figures

Figure 1

Figure 1

Phylogenetic tree based on complete U6 mtDNA genome sequences. A U5b individual has been added in order to root the tree. Nomenclature of individuals as in Table 2. Numbers along links refer to nucleotide positions; suffixes are transversions; i insertions and dd deletion of two nucleotides. Underlining indicates recurrent mutations in U6 subhaplogroup. U presents the following mutations with respect to rCRS: 73, 263, 311i, 750, 1438, 2706, 4769, 7028, 8860, 11467, 11719, 12308, 12372, 14766 and 15326.

Figure 2

Figure 2

Reduced median network relating HVSI sequences of subhaplogroup U6. The central motif (star) differs from rCRS [55,56] at position 16172. Population codes as in Table 2. Numbers along links refer to nucleotide positions minus 16000; suffix indicates a transversion. Individuals marked with * and # additionally present mutations 051 and 048, respectively. Dotted boxes correspond to subgroup U6b1; transversals to U6b; white to U6a; grids to U6a1, and checkered to U6c. Size of boxes is proportional to the number of individuals included. Dotted links represent less probable paths.

Similar articles

Cited by

References

    1. Alimen H. Evolution du climat et des civilisations depuis 40000 ans du nord au sud du Sahara occidental. (Premières conceptions confrontées aux données récentes) Bull L'Assoc Franç L'Êtude Quarternaire. 1987;4:215–227.
    1. Ferembach D. On the origin of the Iberomaurusians (Upper Palaeolithic: North Africa). A new hypothesis. J Hum Evol. 1985;14:393–397.
    1. Newman JL. The peopling of Africa: a geographic interpretation. Yale University Press, New Haven; 1995.
    1. Rando JC, Pinto F, González AM, Hernández M, Larruga JM, Cabrera VM, Bandelt HJ. Mitochondrial DNA analysis of Northwest African populations reveals genetic exchanges with European, Near-Eastern, and sub-Saharan populations. Ann Hum Genet. 1998;62:531–550. doi: 10.1046/j.1469-1809.1998.6260531.x. - DOI - PubMed
    1. Macaulay V, Richards M, Hickey E, Vega E, Cruciani F, Guida V, Scozzari R, Bonné-Tamir B, Sykes B, Torroni A. The emerging tree of west Eurasian mtDNAs: A synthesis of control-region sequences and RFLPs. Am J Hum Genet. 1999;64:232–249. doi: 10.1086/302204. - DOI - PMC - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources