MARCH 2015: Genetic Legacy of Trans-Atlantic Slave Trade: Anthropological and Clinical Contexts

The EUROTAST fellows will be presenting the findings of their research at the upcoming Genetics/Heritage conference, 23-25 April at the International Slavery Museum in Liverpool. Deadline for submission has been extended to March 15. To submit a paper or to attend the conference, visit the Genetics/Heritage website.

Photo by Daniel Tiveau for Center for International Forestry Research (CIFOR).

 Title: Genetic Legacy of Trans-Atlantic Slave Trade: Anthropological and Clinical Contexts

Authors: Petr Triska, Pedro Soares, Viktor Cerny, Beatriz Sierra, Maria G. Guzman, Anavaj Sakuntabhai, Luísa Pereira

African continent harbors a high level of human genetic diversity. The African genetic landscape was shaped throughout numerous migrations, admixture events and selective adaptations to environmental factors and pathogen burden. In Africa, the Sahel belt was one of the most important migration routes, while the Trans-Atlantic Slave Trade introduced the largest forced migration of Africans into other continents. In this study we aimed to investigate admixture patterns along these migration routes and the role of ancestry in adaptation to environment and diseases.

We performed dense (2.5 million) SNP genotyping in 180 Africans from Sahel (west, central and east; sedentary and nomadic), and in 273 Cuban individuals in the context of dengue fever epidemic (controls, asymptomatics and dengue fever patients with and without hemorrhages). SNP data were analyzed for population stratification, linkage disequilibrium patterns, signals of positive selection and local admixture inference.

Ancestry mapping in Sahel indicated uniform African ancestry of Western groups and admixture with non-African ancestry in Central and Eastern ones. Interestingly, East Africans exhibit excess of African ancestry at DARC gene, providing complete resistance to malarial agent Plasmodium vivax, and a peak of non-African ancestry in 2q21 region, including LCT and CXCR4 genes, both strongly selected in European populations in response to lactose tolerance and HIV
infection, respectively. In Cuba, we identified two regions of African ancestry significantly linked with the asymptomatic phenotype, and are now checking its functional implications.

We have shown that detailed ancestry characterization in African and African descendant populations is of high anthropological and medical relevance and can help us to dissect complex host-pathogen interactions.