Genomic diversity in the Dominican Republic: A complex legacy of Taíno, African and European ancestries

Abstract

The Dominican Republic (DR) has long been considered genetically diverse due to its history, which began with resident indigenous groups and then admixture with Europeans and Africans through colonization and slavery in the New World. Later admixture with immigrant populations from Near and South-East Asian populations added to this diversity. Yet, the exact contributions of these populations to the genetic make-up of Dominicans are not yet fully understood. Thus, we aimed to characterize the genomic diversity of Dominicans, determine the ancestral contributions to their genetic diversity, and relate these genetic data to the population history of Hispaniola, the island on which the DR is located. We enrolled a total of 1015 individuals, including 665 males and 350 females, from 25 study sites around the country. DNA samples and genealogical data were obtained with informed consent for all participants, with their DNA samples being surveyed for genomic variation using the GenoChip 2.0+ microarray. Data for haploid genetic markers indicated Dominican mitochondrial DNAs were 78.8% African, 12.1% Native American, and 9.1% West Eurasian in ancestry, whereas their Y-chromosomes were 71% West Eurasian, 28% African, and 1% Native American in ancestry. Dominicans’ autosomal DNA ancestry was 50.3% African, 41.2% European, 3.8% Native American, 2.3% Middle East/Jewish, and 1.8% Central-South-East Asian in origin. The pattern of genetic diversity also evinces sex-biased gene flow, primarily through European males. These data will serve as a reference for future studies exploring Dominican genetic diversity, population history and health.