Department of Life Sciences, Imperial College London
March 26, 2015 3:30, Lindbergh
Assortative mating is the pattern of mates being more similar genetically or phenotypically than expected at random. Within humans, assortative mating between ethnic groups is well known and maintains genetic structure. Within groups, assortative mating is less well understood. Mexicans and Puerto Ricans are have ancestry from Europeans, Africans and Native Americans, and have been found to mate assortatively with respect to these components. This pattern could be caused by several phenomena, including micro-geographical structure in the absence of any preference, actual preference for overall ancestry, or preference for similar phenotypes. We tested for assortative mating with respect to overall ancestry, individual genes, and genes known to be involved in phenotypic variation in Colombians (COL), Puerto Ricans (PUR), Mexican Americans (MXL), African Americans (ASW), Maasai (MKK), Han Chinese (CHS), and European Americans (CEU) using genomic SNP and mated pair data available from the HapMap and 1000 Genomes projects. We find significant assortative mating with respect to overall ancestry in COL, MXL, CHS, and CEU. We then used a sliding window approach to look at individual genes and found that loci with the strongest assortative patterns are often overrepresented for particular biological functions. For example, there are an abundance of genes involved in fertilization with an assortative pattern for European ancestry in MXL. Finally, we looked at genes known to be involved in phenotype, and found that MKK mate assortatively for genes involved in skin color, and ASW mate assortatively for genes involved in skin color and facial morphology.