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Genome-wide and paternal diversity reveal a recent origin of human populations in North Africa.

Fadhlaoui-Zid K, Haber M, Martínez-Cruz B, Zalloua P, Benammar Elgaaied A, Comas D - PLoS ONE (2013)

Bottom Line: In this study, we analyze uniparental and genome-wide markers examining similarities or contrasts in the results and consequently provide a comprehensive description of the evolutionary history of North Africa populations.Our results show that both males and females in North Africa underwent a similar admixture history with slight differences in the proportions of admixture components.We show that genetic diversity of today's North Africans mostly captures patterns from migrations post Last Glacial Maximum and therefore may be insufficient to inform on the initial population of the region during the Middle Paleolithic period.

View Article: PubMed Central - PubMed

Affiliation: Institut de Biologia Evolutiva (Consejo Superior de Investigaciones Científicas-Pompeu Fabra University), Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain ; Laboratoire de Génétique, Immunologie et Pathologies Humaines, Faculté des Sciences de Tunis, Campus Universitaire El Manar II, Université el Manar, Tunis, Tunisia.

ABSTRACT
The geostrategic location of North Africa as a crossroad between three continents and as a stepping-stone outside Africa has evoked anthropological and genetic interest in this region. Numerous studies have described the genetic landscape of the human population in North Africa employing paternal, maternal, and biparental molecular markers. However, information from these markers which have different inheritance patterns has been mostly assessed independently, resulting in an incomplete description of the region. In this study, we analyze uniparental and genome-wide markers examining similarities or contrasts in the results and consequently provide a comprehensive description of the evolutionary history of North Africa populations. Our results show that both males and females in North Africa underwent a similar admixture history with slight differences in the proportions of admixture components. Consequently, genome-wide diversity show similar patterns with admixture tests suggesting North Africans are a mixture of ancestral populations related to current Africans and Eurasians with more affinity towards the out-of-Africa populations than to sub-Saharan Africans. We estimate from the paternal lineages that most North Africans emerged ∼15,000 years ago during the last glacial warming and that population splits started after the desiccation of the Sahara. Although most North Africans share a common admixture history, the Tunisian Berbers show long periods of genetic isolation and appear to have diverged from surrounding populations without subsequent mixture. On the other hand, continuous gene flow from the Middle East made Egyptians genetically closer to Eurasians than to other North Africans. We show that genetic diversity of today's North Africans mostly captures patterns from migrations post Last Glacial Maximum and therefore may be insufficient to inform on the initial population of the region during the Middle Paleolithic period.

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Genome-wide population structure.A) Principal component analysis of ∼44,000 SNPs showing the top two components. B) Maximum likelihood tree showing populations relationships.
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pone-0080293-g004: Genome-wide population structure.A) Principal component analysis of ∼44,000 SNPs showing the top two components. B) Maximum likelihood tree showing populations relationships.

Mentions: PCA on genome-wide SNPs (Figure 4A) shows that North Africans are diverse and closer to Middle Easterners and Europeans than to Sub-Saharan Africans. Egyptians appear the closest to Middle Easterners and Europeans while South Moroccans are drawn towards Sub-Saharans. Tunisian samples (Chenini-Douiret Berbers) form an orthogonal cluster close but distinct from other North Africans which mostly appear in overlapping clusters.


Genome-wide and paternal diversity reveal a recent origin of human populations in North Africa.

Fadhlaoui-Zid K, Haber M, Martínez-Cruz B, Zalloua P, Benammar Elgaaied A, Comas D - PLoS ONE (2013)

Genome-wide population structure.A) Principal component analysis of ∼44,000 SNPs showing the top two components. B) Maximum likelihood tree showing populations relationships.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3842387&req=5

pone-0080293-g004: Genome-wide population structure.A) Principal component analysis of ∼44,000 SNPs showing the top two components. B) Maximum likelihood tree showing populations relationships.
Mentions: PCA on genome-wide SNPs (Figure 4A) shows that North Africans are diverse and closer to Middle Easterners and Europeans than to Sub-Saharan Africans. Egyptians appear the closest to Middle Easterners and Europeans while South Moroccans are drawn towards Sub-Saharans. Tunisian samples (Chenini-Douiret Berbers) form an orthogonal cluster close but distinct from other North Africans which mostly appear in overlapping clusters.

Bottom Line: In this study, we analyze uniparental and genome-wide markers examining similarities or contrasts in the results and consequently provide a comprehensive description of the evolutionary history of North Africa populations.Our results show that both males and females in North Africa underwent a similar admixture history with slight differences in the proportions of admixture components.We show that genetic diversity of today's North Africans mostly captures patterns from migrations post Last Glacial Maximum and therefore may be insufficient to inform on the initial population of the region during the Middle Paleolithic period.

View Article: PubMed Central - PubMed

Affiliation: Institut de Biologia Evolutiva (Consejo Superior de Investigaciones Científicas-Pompeu Fabra University), Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain ; Laboratoire de Génétique, Immunologie et Pathologies Humaines, Faculté des Sciences de Tunis, Campus Universitaire El Manar II, Université el Manar, Tunis, Tunisia.

ABSTRACT
The geostrategic location of North Africa as a crossroad between three continents and as a stepping-stone outside Africa has evoked anthropological and genetic interest in this region. Numerous studies have described the genetic landscape of the human population in North Africa employing paternal, maternal, and biparental molecular markers. However, information from these markers which have different inheritance patterns has been mostly assessed independently, resulting in an incomplete description of the region. In this study, we analyze uniparental and genome-wide markers examining similarities or contrasts in the results and consequently provide a comprehensive description of the evolutionary history of North Africa populations. Our results show that both males and females in North Africa underwent a similar admixture history with slight differences in the proportions of admixture components. Consequently, genome-wide diversity show similar patterns with admixture tests suggesting North Africans are a mixture of ancestral populations related to current Africans and Eurasians with more affinity towards the out-of-Africa populations than to sub-Saharan Africans. We estimate from the paternal lineages that most North Africans emerged ∼15,000 years ago during the last glacial warming and that population splits started after the desiccation of the Sahara. Although most North Africans share a common admixture history, the Tunisian Berbers show long periods of genetic isolation and appear to have diverged from surrounding populations without subsequent mixture. On the other hand, continuous gene flow from the Middle East made Egyptians genetically closer to Eurasians than to other North Africans. We show that genetic diversity of today's North Africans mostly captures patterns from migrations post Last Glacial Maximum and therefore may be insufficient to inform on the initial population of the region during the Middle Paleolithic period.

Show MeSH