European admixture on the Micronesian island of Kosrae: lessons from complete genetic information.
The architecture of natural variation present in a contemporary population is a result of multiple population genetic forces, including population bottleneck and expansion, selection, drift, and admixture. We seek to untangle the contribution of admixture to genetic diversity on the Micronesian island of Kosrae. Toward this goal, we used a complete genetic approach by combining a dense genome-wide map of 100,000 single-nucleotide polymorphisms (SNPs) with data from uniparental markers from the mitochondrial genome and the nonrecombining portion of the Y chromosome. These markers were typed in approximately 3200 individuals from Kosrae, representing 80% of the adult population of the island. We developed novel software that uses SNP data to delineate ancestry for individual segments of the genome. Through this analysis, we determined that 39% of Kosraens have some European ancestry. However, the vast majority of admixed individuals (77%) have European alleles spanning less than 10% of their genomes. Data from uniparental markers show most of this admixture to be male, introduced in the late nineteenth century. Furthermore, pedigree analysis shows that the majority of European admixture on Kosrae is because of the contribution of one individual. This approach shows the benefit of combining information from autosomal and uniparental polymorphisms and provides new methodology for determining ancestry in a population.
Department of Human and Molecular Genetics, Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA. pbonnen@bcm.edu
Penelope E
PE
Bonnen
Jennifer K
JK
Lowe
David M
DM
Altshuler
Jan L
JL
Breslow
Markus
M
Stoffel
Jeffrey M
JM
Friedman
Itsik
I
Pe'er
D041322:Chromosomes, Human, Y / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D005060:Europe; D005260:Female; D005788:Gene Pool; D005819:Genetic Markers; D005828:Genetics, Population; D015894:Genome, Human / Q000235:genetics; D005843:Geography; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D040582:Inheritance Patterns / Q000235:genetics; D008297:Male; D008849:Micronesia; D010375:Pedigree; D010802:Phylogeny; D012984:Software; D013997:Time Factors
D004272:DNA, Mitochondrial; D005819:Genetic Markers