title: mtDNA variation in Inuit populations of Greenland and Canada: migration history and population structure.
abstract: We examined 395 mtDNA control-region sequences from Greenlandic Inuit and Canadian Kitikmeot Inuit with the aim of shedding light on the migration history that underlies the present geographic patterns of genetic variation at this locus in the Arctic. In line with previous studies, we found that Inuit populations carry only sequences belonging to haplotype clusters A2 and D3. However, a comparison of Arctic populations from Siberia, Canada, and Greenland revealed considerable differences in the frequencies of these haplotypes. Moreover, large sample sizes and regional information about birthplaces of maternal grandmothers permitted the detection of notable differences in the distribution of haplotypes among subpopulations within Greenland. Our results cast doubt on the prevailing hypothesis that contemporary Inuit trace their all of their ancestry to so-called Thule groups that expanded from Alaska about 800-1,000 years ago. In particular, discrepancies in mutational divergence between the Inuit populations and their putative source mtDNA pool in Siberia/Alaska for the two predominant haplotype clusters, A2a and A2b, are more consistent with the possibility that expanding Thule groups encountered and interbred with existing Dorset populations in Canada and Greenland.
authors.affiliation: deCODE Genetics, Inc., 101 Reykjavik, Iceland. agnar@decode.is
authors.forename: Agnar
authors.initials: A
authors.lastname: Helgason
authors.forename: Gísli
authors.initials: G
authors.lastname: Pálsson
authors.forename: Henning Sloth
authors.initials: HS
authors.lastname: Pedersen
authors.forename: Emily
authors.initials: E
authors.lastname: Angulalik
authors.forename: Ellen Dröfn
authors.initials: ED
authors.lastname: Gunnarsdóttir
authors.forename: Bryndís
authors.initials: B
authors.lastname: Yngvadóttir
authors.forename: Kári
authors.initials: K
authors.lastname: Stefánsson
mesh_terms: D002170:Canada; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics* / Q000266:history*; D004641:Emigration and Immigration / Q000266:history*; D014644:Genetic Variation / Q000235:genetics*; D005828:Genetics, Population / Q000379:methods; D006116:Greenland; D006239:Haplotypes / Q000235:genetics; D049674:History, 21st Century; D049690:History, Ancient; D006801:Humans; D004930:Inuit / Q000235:genetics* / Q000266:history*; D019901:Locus Control Region / Q000235:genetics; D010802:Phylogeny
chemical_list: D004272:DNA, Mitochondrial