Contrasting Maternal, Paternal, and Biparental Ancestry of Populations From the Caribbean Coast of Colombia

OBJECTIVES: The current Caribbean Colombian population is the result of migration processes and admixture that occurred throughout the country's history. The aim of this study was to investigate genetic ancestry gradients throughout the Caribbean territory, with a higher Native American ancestry expected in inland areas compared to coastal cities. Simultaneously, since the genotyping methodology used included markers of forensic relevance for predicting population of origin and pigmentary phenotypic characteristics, this study also tested the main tools commonly applied in forensic contexts. MATERIALS AND METHODS: Uniparental and biparental genetic ancestries of individuals from the Bolívar Department, in the Caribbean Colombian region, were investigated. A total of 64 samples were collected from Coast, Center, and Inland regions. Genotyping was performed with a newly developed PCR-based targeted MPS tool called COMBO, targeting over 1000 polymorphisms along mtDNA, Y chromosome, and autosomes. RESULTS AND DISCUSSION: The Coast and Center regions showed similar ancestry profiles. The Inland region displayed a contrasting pattern, being mainly composed of Native American maternal lineages and European paternal lineages. Statistically significant differences in mtDNA and AIM-SNP compositions were only found between the Coast and Inland regions, absent for the Y chromosome. The results obtained regarding the prediction of eye, hair, and skin color were as expected based on the ancestry profile of the population. Biogeographic ancestry prediction tools have presented challenges in assigning individuals to the American metapopulation, highlighting the need for better reference datasets from South America, given the great heterogeneity in the admixture patterns they present.