Background: There are over 2000 genetically diverse ethnolinguistic groups in Africa that could help decipher human evolutionary history and the genetic basis of phenotypic variation. We have analysed 298 genomes from Niger Congo populations from six sub Saharan African countries (Uganda, Democratic Republic of Congo, Cameroon, Zambia, Ivory Coast, Guinea) and a Nilo Saharan population from Uganda. These samples were collected as part of the TrypanoGEN consortium project http://www.trypanogen.net. Results: The population genetic structure of the 298 individuals revealed four clusters which correlated with ethnolinguistic group and geographical latitude, that is, West African Niger-Congo A, Central African Niger Congo, East African Niger-Congo B and the NiloSaharan. We observed a spatial distribution of positive natural selection signatures in genes associated with AIDS, Tuberculosis, Malaria and Human African Trypanosomiasis among the TrypanoGEN samples. Having observed a marked difference between the NiloSaharan Lugbara and Niger Congo populations, we identified four genes [APOBEC3G, TOP2B, CAPN9, LANCL2, (iHS -log p > 3.0, Rsb -log p > 3.0, Fst > 0.1 Bonferroni p > 1.8x10e4)], which are highly differentiated between the two ethnic groups and under positive selection in the Lugbara population. Conclusion: The signatures that differentiate ethnically distinct populations provide information on the specific ecological adaptations with respect to disease history and susceptibility/ resistance; as demonstrated in this study where APOBEG3G is believed to be involved in the susceptibility of the Nilo Saharan Lugbara population to Hepatitis B virus infection.
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Migrations of Niger-Congo speakers and population sizes and cross-coalescence rates.
Ivorians and Guinean populations retain evidence of patterns of panmixia till about 10kya other populations showing signs of gradual separation. (maybe Confound by admixture.) (And as expected) Sampled populations in the show a drop or halt in population growth during the colonial era.
Besides the good medical stuff it is nice to see genomes from another Central Sudanic population.
They seem to rather freely conflate the Lugbara with proper Nilotes (like Maasai) without actually including any Nilotes in the comparison. Hopefully in the future we will see these Lugbara together with Sara, Dinka, and others in a large African sample, which might reveal some Central African structure.
Posted by Clyde Winters (Member # 10129) on :
The paper is interesting but I disagree with its conclusions. First of all the Niger-Congo population originated during the Ounanian period in the Sahara Sahel, they later migrated into Chad-Cameroon and founded the civilization of Maa. They remained there until the Sahara became more arid. Due to aridity the Niger-Congo speakers spread into the Nile Valley and beyond after 3000. After the decline of Egypt, the Bantu began to spread into Central and Southern Africa. See: web page
