Insights from pattern of mtDNA variation into the genetic history of São Tomé e Prı́ncipe

Abstract

Sequence data from the hypervariable segments I (HVS-I) and II (HVS-II) was obtained for 30 Angolares, 35 Forros and 38 Tongas, three self-reported ethnic groups from São Tomé e Prı́ncipe, an African archipelago (Gulf of Guinea) whose settlement begun in the late 15th century. The repertory of mtDNA lineages denoted a fully African maternal pool primarily arisen from a Central/Southwestern substratum. The absence of any lineages of putative European descent means that the European impact at the mitochondrial pool was virtually nil. Angolares showed a clear reduction of mtDNA diversity and a slight genetic differentiation relatively to Tongas or Forros, whereas the two last groups did not present any signs of genetic boundaries between each other. The data now obtained reinforce the depiction of genetic substructuring in São Tomé e Prı́ncipe previously derived from Y-chromosome STRs.