At the southeast fringe of the Bantu expansion: genetic diversity and phylogenetic relationships to other sub-Saharan tribes

Diane Rowold; Ralph Garcia-Bertrand; Silvia Calderon; Luis Rivera; David Perez Benedico; Miguel A Alfonso Sanchez; Shilpa Chennakrishnaiah; Mangela Varela; Rene J Herrera

doi:10.1016/j.mgene.2014.08.003

At the southeast fringe of the Bantu expansion: genetic diversity and phylogenetic relationships to other sub-Saharan tribes

Meta Gene. 2014 Oct 2:2:670-85. doi: 10.1016/j.mgene.2014.08.003. eCollection 2014 Dec.

Authors

Diane Rowold¹, Ralph Garcia-Bertrand², Silvia Calderon³, Luis Rivera⁴, David Perez Benedico⁵, Miguel A Alfonso Sanchez⁶, Shilpa Chennakrishnaiah⁷, Mangela Varela², Rene J Herrera²

Affiliations

¹ Foundation for Applied Molecular Evolution, Gainesville, FL 32601, USA.
² Biology Department, Colorado College, Colorado Springs, CO 80903, USA.
³ College of Dentistry, New York University, New York, NY 10010, USA.
⁴ College of Health Sciences, Florida International University, Miami, FL 33199, USA.
⁵ Department of Biology, Miami Dade College, Miami, FL 33199, USA.
⁶ Departamento de Genética y Antropología Fısica, Facultad de Ciencia y Tecnología, Universidad del País Vasco, 48080 Bilbao, Bizkaia, Spain.
⁷ Department of Human Genetics, McGill University, Montreal, Quebec H3Z 2Z3, Canada.

Abstract

Here, we present 12 loci paternal haplotypes (Y-STR profiles) against the backdrop of the Y-SNP marker system of Bantu males from the Maputo Province of Southeast Africa, a region believed to represent the southeastern fringe of the Bantu expansion. Our Maputo Bantu group was analyzed within the context of 27 geographically relevant reference populations in order to ascertain its genetic relationship to other Bantu and non Bantu (Pygmy, Khoisan and Nilotic) sub-equatorial tribes from West and East Africa. This study entails statistical pair wise comparisons and multidimensional scaling based on YSTR Rst distances, network analyses of Bantu (B2a-M150) and Pygmy (B2b-M112) lineages as well as an assessment of Y-SNP distribution patterns. Several notable findings include the following: 1) the Maputo Province Bantu exhibits a relatively close paternal affinity with both east and west Bantu tribes due to high proportion of Bantu Y chromosomal markers, 2) only traces of Khoisan (1.3%) and Pygmy (1.3%) markers persist in the Maputo Province Bantu gene pool, 3) the occurrence of R1a1a-M17/M198, a member of the Eurasian R1a-M420 branch in the population of the Maputo Province, may represent back migration events and/or recent admixture events, 4) the shared presence of E1b1b1-M35 in all Tanzanian tribes examined, including Bantu and non-Bantu groups, in conjunction with its nearly complete absence in the West African populations indicate that, in addition to a shared linguistic, cultural and genetic heritage, geography (e.g., east vs. west) may have impacted the paternal landscape of sub-Saharan Africa, 5) the admixture and assimilation processes of Bantu elements were both highly complex and region-specific.

Keywords: Africa; Bantu; MAP, Maputo Province; MDS, multi-dimensional scaling; MJ, medial joining; PCR, polymerase chain reaction; Phylogenetics; Population genetics; RFLP, restriction fragment length polymorphism; SNP, single nucleotide polymorphism; STR, short tandem repeat; TMRCA, time of most recent common ancestor; Y-STRs; Y-chromosome; mtDNA, mitochondrial DNA.