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Geneaology DNA Testing - Female mtDNA healthanddna.com |
In human mitochondrial genetics, Haplogroup U is a human mitochondrial DNA (mtDNA) haplogroup.
[edit] OriginHaplogroup U (named 'Europa clan' by Stephen Oppenheimer[2]) descends from a woman, in the Haplogroup R (mtDNA) branch of the phylogenetic tree, who lived around 55,000 years ago. Her descendants gave birth to several different subgroups, some of which exhibit specific geographic homelands. The old age has led to a wide distribution of the descendant subgroups that harbor specific European, northern African, Indian, Arab, northern Caucasus Mountains and the Near East clades.[3] [edit] DistributionHaplogroup U is subdivided into Haplogroups U1-U8. Haplogroup K is a subclade of U8.[4] [edit] Haplogroup U1Haplogroup U1 (named 'Una' by Bryan Sykes) seems to appear mostly in the Middle East, however low frequency results appear scattered throughout Europe particularly in the Mediterranean. U1a in particular is found from India to Europe, but is extremely rare among the northern and Atlantic fringes of Europe including the British Isles and Scandinavia. Several examples in Tuscany have been noted. In India U1a has been found in the Kerala region and the west. U1b has a similar spread but is rarer than U1a. Some examples of U1b have been found among Jewish diaspora. U1a and U1b appear in equal frequency in eastern Europe.[5] [edit] Haplogroup U2Haplogroup U2 (named 'Uta' by Bryan Sykes) is most common in South Asia[6] but also found in low frequency in Central and West Asia, as well as in Europe.[7] [edit] Haplogroup U3Haplogroup U3 (named 'Uma' by Bryan Sykes) is defined by the HVR1 transition A16343G. It is found at low levels throughout Europe (about 1% of the population), the Near East (about 2.5% of the population), and Central Asia (1%). U3 is present at higher levels among populations in the Caucasus (about 6%) and among Lithuanian Romani, Polish Romani, and Spanish Romani populations (36-56%).[8][9][10] [edit] Haplogroup U4Haplogroup U4 (named 'Ulrike' by Bryan Sykes) has its origin in the Upper Palaeolithic, dating to approximately 25,000 years ago. It is widely distributed in Europe, and has been implicated in the expansion of modern humans into Europe occurring before the Last Glacial Maximum. [edit] Haplogroup U5Among the oldest mtDNA haplogroups found in European remains of Homo sapiens is U5. The age of U5 is estimated at 50,000 but could be as old as 60,500 years. Approximately 11% of total Europeans and 10% of European-Americans are in haplogroup U5. The presence of haplogroup U5 in Europe pre-dates the expansion of agriculture in Europe. Bryan Sykes' popular book The Seven Daughters of Eve calculated that it arose 45,000-50,000 years ago in Delphi, Greece and named the originator of haplogroup U5 Ursula. However the details related to location and age are speculative. Barbujani and Bertorelle estimate the age of haplogroup U5 as about 52,000 years ago, being the oldest subclade of haplogroup U,[11]. U5 has been found in human remains dating from the Mesolithic in England, Germany, Lithuania, Poland, Portugal and Russia.[12] Haplogroup U5 and its subclades U5a and U5b form the highest population concentrations in the far north, in Sami, Finns, and Estonians, but it is spread widely at lower levels throughout Europe. This distribution, and the age of the haplogroup, indicate individuals from this haplogroup were part of the initial expansion tracking the retreat of ice sheets from Europe ~10kya. Haplogroup U5 is found also in small frequencies and at much lower diversity in the Near East and parts of Africa, suggesting back-migration of people from northern Europe to the south.[3] Mitochondrial haplogroup U5a has also been associated with HIV infected individuals displaying accelerated progression to AIDS and death.[13]
[edit] Haplogroup U6Haplogroup U6 (named 'Ulla' by Bryan Sykes) is a group of people who descend from a woman in the Haplogroup R (mtDNA) branch of the phylogenetic tree. It is common (around 10% of the people) [3] in North Africa (with a maximum of 29% in Algerian Berbers[17]) and the Canary Islands (18%). It is also found in the Iberian peninsula, where it has the highest diversity (10 out of 19 sublineages are only found in this region and not in Africa),[17] Eastern Africa and occasionally in other locations. In spite of the highest diversity of Iberian U6, Maca-Meyer argues for an East African origin of this clade based on the highest diversity of subclade U6a in that region,[17] where it would have arrived from West Asia. She estimates the age of U6 between 25,000 and 66,000 years BP. U6 has three main subclades:[17]
U6a and U6b share a common basal mutation (16219) that is not present in U6c. [edit] Haplogroup U7Many European populations lack Haplogroup U7 (named 'Ulaana' by Bryan Sykes), but its frequency climbs over 4% in the Near East and up to 5% in Pakistan, reaching nearly 10% level in Iranians. In India, haplogroup U7 frequency peaks at over 12% in Gujarat, the westernmost state of India, while for the whole of India its frequency stays around 2%. Expansion times and haplotype diversities for the Indian and Near and Middle Eastern U7 mtDNAs are strikingly similar. The possible homeland of this haplogroup spans Indian Gujarat and Iran because from there its frequency declines steeply both to the east and to the west. If the origin were in Iran rather than in India, then its equally high frequency as well as diversity in Gujarat favors a scenario whereby U7 has been introduced to the coastal western India either very early, or by multiple founders.[18] [edit] Haplogroup U8
[edit] Haplogroup KHaplogroup K (named 'Katrine' by Bryan Sykes) makes up a sizeable fraction of European and West Asian mtDNA lineages. It is now known it is actually a subclade of haplogroup U8[4], and is believed to have first arisen in northeastern Italy. Haplogroup UK shows some evidence of being highly protective against AIDS progression.[13] [edit] Subclades[edit] TreeThis phylogenetic tree of haplogroup U subclades is based on the paper by Mannis van Oven and Manfred Kayser Updated comprehensive phylogenetic tree of global human mitochondrial DNA variation[1] and subsequent published research.
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