mtDNA structure: the women who formed the Brazilian Northeast

BMC Evolutionary Biology

Research Article

Raquel Montenegro¹  Vivian Silbiger²  Diego Santos²  Lorenna Costa²  Giovanny Pinto³  Thayson Lopes³  France Keiko Yoshioka³  Camile Lopes⁴  Ana Paula Schaan⁴  Antonio Modesto⁴  Bruno D. A. Souza⁴  Marcos Amador⁴  Ândrea Ribeiro-dos-Santos⁵  Sílvia Helena Rabenhorst⁶ 

[1] Center of Research and Drug Development, Federal University of Ceará, 60430-270, Fortaleza, CE, Brazil;Clinical and Toxicological Analyses Department, Federal University of Rio Grande do Norte, 59300-000, Natal, RN, Brazil;Genetics and Molecular Biology Laboratory, Federal University of Piauí, 64202-020, Parnaíba, PI, Brazil;Human and Medical Genetics Laboratory, Federal University of Pará, Av. Augusto Corrêa, 01 – Cidade Universitária Prof. José Silveira Netto – Guamá, 66075-110, Belém, PA, Brazil;Human and Medical Genetics Laboratory, Federal University of Pará, Av. Augusto Corrêa, 01 – Cidade Universitária Prof. José Silveira Netto – Guamá, 66075-110, Belém, PA, Brazil;Center of Oncological Research, Federal University of Pará, 66073-005, Belém, PA, Brazil;Pathology and Legal Medicine Department, Federal University of Ceará, 60020-181, Fortaleza, CE, Brazil;

关键词: mtDNA lineages;    Northeastern Brazil;    Genetic diversity;    Migration pattern;    Population admixture;    Asymmetric colonization;   

DOI  :  10.1186/s12862-017-1027-7

 received in 2017-02-22, accepted in 2017-07-26,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundThe distribution of mitochondrial DNA (mtDNA) lineages in Brazil is heterogeneous due to different regional colonization dynamics. Northeastern Brazil, although being an important region in terms of human imigration and ethnic admixture, has little information regarding its population mtDNA composition. Here, we determine which mitochondrial lineages contributed to the formation of the Northeastern Brazilian population. Our sample consisted of 767 individuals distributed as follows i) 550 individuals from eight Northeastern states (Piauí, Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Alagoas, Sergipe, and Bahia) which were sequenced for mtDNA hypervariable segments I, II, and III; ii) 217 individuals from Alagoas and Pernambuco (previously published data). Data analysis was performed through sequence alignment and Haplogrep 2.0 haplogroup assignment tools. Furthermore, maternal ancestry distribution was contextualized and, when possible, related to historical events to better understand the biological interactions and population dynamics that occurred in this region since the beginning of colonization.ResultsUnexpectedly, Amerindian mitochondrial ancestry was the highest in the Northeastern region overall, followed by African, European and non-Amerindian Asian, unlike previous results for this region. Alagoas and Pernambuco states, however, showed a larger African mtDNA frequency. The Northeastern region showed an intraregional heterogeneous distribution regarding ancestral groups, in which states/mesoregions located to the north had a prevalent Amerindian ancestral frequency and those to the south had predominance of African ancestry. Moreover, results showed great diversity of European haplogroups and the presence of non-Amerindian Asian haplogroups.ConclusionsOur findings are in disagreement with previous investigations that suggest African mitochondrial ancestry is the most prevalent in the Brazilian Northeast. The predominance of Amerindian lineages exemplifies the importance of indigenous women in the formation of the population, despite intense African slave entry and conflicts with European settlers. The variable distribution of ancestral groups observed in the Northeast is in accordance with historical records showing the similarities with colonization dynamics occurred in the Amazon region and the Brazilian Southeast. Moreover, the variety of European haplogroups suggests multiple origins of founding groups, specially those found in Western European populations.

【 授权许可】

CC BY   
© The Author(s). 2017