title: Ancestry, admixture and fitness in Colombian genomes.
abstract: The human dimension of the Columbian Exchange entailed substantial genetic admixture between ancestral source populations from Africa, the Americas and Europe, which had evolved separately for many thousands of years. We sought to address the implications of the creation of admixed American genomes, containing novel allelic combinations, for human health and fitness via analysis of an admixed Colombian population from Medellin. Colombian genomes from Medellin show a wide range of three-way admixture contributions from ancestral source populations. The primary ancestry component for the population is European (average = 74.6%, range = 45.0%-96.7%), followed by Native American (average = 18.1%, range = 2.1%-33.3%) and African (average = 7.3%, range = 0.2%-38.6%). Locus-specific patterns of ancestry were evaluated to search for genomic regions that are enriched across the population for particular ancestry contributions. Adaptive and innate immune system related genes and pathways are particularly over-represented among ancestry-enriched segments, including genes (HLA-B and MAPK10) that are involved in defense against endemic pathogens such as malaria. Genes that encode functions related to skin pigmentation (SCL4A5) and cutaneous glands (EDAR) are also found in regions with anomalous ancestry patterns. These results suggest the possibility that ancestry-specific loci were differentially retained in the modern admixed Colombian population based on their utility in the New World environment.
authors.affiliation: 1] School of Biology, Georgia Institute of Technology, Atlanta, GA 30332, USA [2] PanAmerican Bioinformatics Institute, Cali, Valle del Cauca, Colombia [3] BIOS Centro de Bioinformática y Biología Computacional, Manizales, Caldas, Colombia.
authors.forename: Lavanya
authors.initials: L
authors.lastname: Rishishwar
authors.affiliation: School of Biology, Georgia Institute of Technology, Atlanta, GA 30332, USA.
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Conley
authors.affiliation: School of Biology, Georgia Institute of Technology, Atlanta, GA 30332, USA.
authors.forename: Charles H
authors.initials: CH
authors.lastname: Wigington
authors.affiliation: School of Biology, Georgia Institute of Technology, Atlanta, GA 30332, USA.
authors.forename: Lu
authors.initials: L
authors.lastname: Wang
authors.affiliation: 1] PanAmerican Bioinformatics Institute, Cali, Valle del Cauca, Colombia [2] Biomedical Research Institute, Universidad Libre, Cali, Valle del Cauca, Colombia [3] Regenerar - Center of Excellence for Regenerative and Personalized Medicine, Cali, Valle del Cauca, Colombia.
authors.forename: Augusto
authors.initials: A
authors.lastname: Valderrama-Aguirre
authors.affiliation: 1] School of Biology, Georgia Institute of Technology, Atlanta, GA 30332, USA [2] PanAmerican Bioinformatics Institute, Cali, Valle del Cauca, Colombia [3] BIOS Centro de Bioinformática y Biología Computacional, Manizales, Caldas, Colombia.
authors.forename: I King
authors.initials: IK
authors.lastname: Jordan
mesh_terms: D000349:Africa; D000483:Alleles; D044383:Black People / Q000235:genetics; D005006:Ethnicity / Q000235:genetics*; D005060:Europe; D005828:Genetics, Population / Q000379:methods; D015894:Genome, Human / Q000235:genetics*; D023281:Genomics; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D044465:White People / Q000235:genetics