Origin and diffusion of mtDNA haplogroup X.
A maximum parsimony tree of 21 complete mitochondrial DNA (mtDNA) sequences belonging to haplogroup X and the survey of the haplogroup-associated polymorphisms in 13,589 mtDNAs from Eurasia and Africa revealed that haplogroup X is subdivided into two major branches, here defined as "X1" and "X2." The first is restricted to the populations of North and East Africa and the Near East, whereas X2 encompasses all X mtDNAs from Europe, western and Central Asia, Siberia, and the great majority of the Near East, as well as some North African samples. Subhaplogroup X1 diversity indicates an early coalescence time, whereas X2 has apparently undergone a more recent population expansion in Eurasia, most likely around or after the last glacial maximum. It is notable that X2 includes the two complete Native American X sequences that constitute the distinctive X2a clade, a clade that lacks close relatives in the entire Old World, including Siberia. The position of X2a in the phylogenetic tree suggests an early split from the other X2 clades, likely at the very beginning of their expansion and spread from the Near East.
Department of Evolutionary Biology, Institute of Molecular and Cell Biology, Tartu University and Estonian Biocentre, Tartu, Estonia. mreidla@ebc.ee
Maere
M
Reidla
Toomas
T
Kivisild
Ene
E
Metspalu
Katrin
K
Kaldma
Kristiina
K
Tambets
Helle-Viivi
HV
Tolk
Jüri
J
Parik
Eva-Liis
EL
Loogväli
Miroslava
M
Derenko
Boris
B
Malyarchuk
Marina
M
Bermisheva
Sergey
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Zhadanov
Erwan
E
Pennarun
Marina
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Gubina
Maria
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Golubenko
Larisa
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Damba
Sardana
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Fedorova
Vladislava
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Gusar
Elena
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Grechanina
Ilia
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Mikerezi
Jean-Paul
JP
Moisan
André
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Chaventré
Elsa
E
Khusnutdinova
Ludmila
L
Osipova
Vadim
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Stepanov
Mikhail
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Voevoda
Alessandro
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Achilli
Chiara
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Rengo
Olga
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Rickards
Gian Franco
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De Stefano
Surinder
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Papiha
Lars
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Beckman
Branka
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Janicijevic
Pavao
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Rudan
Nicholas
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Anagnou
Emmanuel
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Michalodimitrakis
Slawomir
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Koziel
Esien
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Usanga
Tarekegn
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Geberhiwot
Corinna
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Herrnstadt
Neil
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Howell
Antonio
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Richard
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Villems
D000349:Africa; D001208:Asia; D004272:DNA, Mitochondrial / Q000235:genetics*; D004641:Emigration and Immigration; D005060:Europe; D014644:Genetic Variation / Q000235:genetics*; D006239:Haplotypes / Q000235:genetics*; D006801:Humans; D007198:Indians, North American / Q000235:genetics; D010802:Phylogeny; D011110:Polymorphism, Genetic / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics
D004272:DNA, Mitochondrial