Haplogroup J (mtDNA) - AbsoluteAstronomy.com

Human mitochondrial genetics

Human mitochondrial genetics is the study of the genetics of the DNA contained in human mitochondria. Mitochondria are small structures in cells that generate energy for the cell to use, and are hence referred to as the "powerhouses" of the cell....

, Haplogroup J is a human mitochondrial DNA (mtDNA) haplogroup.
Haplogroup J derives from the haplogroup JT

Haplogroup JT (mtDNA)

In human mitochondrial genetics, Haplogroup JT is a human mitochondrial DNA haplogroup.-Origin:A descendant of the macro-haplogroup R, Haplogroup JT is the ancestral haplogroup to mitochondrial haplogroups J and T.-Tree:...

, which also gave rise to Haplogroup T

Haplogroup T (mtDNA)

In human mitochondrial genetics, Haplogroup T is a human mitochondrial DNA haplogroup.-Known Origins:Mitochondrial Haplogroup T derives from the haplogroup JT, which also gave rise to haplogroup J...

. In his popular book The Seven Daughters of Eve
The Seven Daughters of Eve
The Seven Daughters of Eve is a book by Bryan Sykes that presents the theory of human mitochondrial genetics to a general audience...

, Bryan Sykes

Bryan Sykes

Bryan Sykes is a former Professor of Human Genetics at the University of Oxford and a current Fellow of Wolfson College.Sykes published the first report on retrieving DNA from ancient bone...

named the originator of this mtDNA haplogroup Jasmine. Within the field of medical genetics

Medical genetics

Medical genetics is the specialty of medicine that involves the diagnosis and management of hereditary disorders. Medical genetics differs from Human genetics in that human genetics is a field of scientific research that may or may not apply to medicine, but medical genetics refers to the...

, certain polymorphisms specific to haplogroup J have been associated with Leber's hereditary optic neuropathy

Leber's hereditary optic neuropathy

Leber’s hereditary optic neuropathy or Leber optic atrophy is a mitochondrially inherited degeneration of retinal ganglion cells and their axons that leads to an acute or subacute loss of central vision; this affects predominantly young adult males...

Origin

Around 45,000 years before present, a mutation took place in the DNA of a woman who lived in the Near East

Near East

The Near East is a geographical term that covers different countries for geographers, archeologists, and historians, on the one hand, and for political scientists, economists, and journalists, on the other...

or Caucasus

Caucasus

The Caucasus, also Caucas or Caucasia , is a geopolitical region at the border of Europe and Asia, and situated between the Black and the Caspian sea...

. Further mutations took place in the J line which can be identified as J1a1 (27,000 yrs ago), J2a (19,000 yrs ago), J2b2 (16,000 years ago), J2b3 (5,800 yrs ago), etc. Haplogroup J (along with ‘T’) is associated with the spread of farming and herding in Europe during the Neolithic Era (8,000-10,000 yrs ago).

Coalescence time estimates for the subclades of mitochondrial haplogroup J
Subclade	European coalescence time	Near East coalescence time
J1a1	27,300 years (± Margin of error The margin of error is a statistic expressing the amount of random sampling error in a survey's results. The larger the margin of error, the less faith one should have that the poll's reported results are close to the "true" figures; that is, the figures for the whole population... 8,000 years)	17,700 years (± Margin of error The margin of error is a statistic expressing the amount of random sampling error in a survey's results. The larger the margin of error, the less faith one should have that the poll's reported results are close to the "true" figures; that is, the figures for the whole population... 2,500 years)
J1a2	7,700 years (± Margin of error The margin of error is a statistic expressing the amount of random sampling error in a survey's results. The larger the margin of error, the less faith one should have that the poll's reported results are close to the "true" figures; that is, the figures for the whole population... 3,500 years)	—
J1b	5,000 years (± Margin of error The margin of error is a statistic expressing the amount of random sampling error in a survey's results. The larger the margin of error, the less faith one should have that the poll's reported results are close to the "true" figures; that is, the figures for the whole population... 2,200 years)	23,300 years (± Margin of error The margin of error is a statistic expressing the amount of random sampling error in a survey's results. The larger the margin of error, the less faith one should have that the poll's reported results are close to the "true" figures; that is, the figures for the whole population... 4,300 years)
J2a	19,200 years(± Margin of error The margin of error is a statistic expressing the amount of random sampling error in a survey's results. The larger the margin of error, the less faith one should have that the poll's reported results are close to the "true" figures; that is, the figures for the whole population... 6,900 years)	—
J2b1	—	15,000 years (± Margin of error The margin of error is a statistic expressing the amount of random sampling error in a survey's results. The larger the margin of error, the less faith one should have that the poll's reported results are close to the "true" figures; that is, the figures for the whole population... 5000 years)
J2b2	161,600* years (± Margin of error The margin of error is a statistic expressing the amount of random sampling error in a survey's results. The larger the margin of error, the less faith one should have that the poll's reported results are close to the "true" figures; that is, the figures for the whole population... 8,100 years)	16,000 years (± Margin of error The margin of error is a statistic expressing the amount of random sampling error in a survey's results. The larger the margin of error, the less faith one should have that the poll's reported results are close to the "true" figures; that is, the figures for the whole population... 5,700 years)
J2b3	5,800 years (± Margin of error The margin of error is a statistic expressing the amount of random sampling error in a survey's results. The larger the margin of error, the less faith one should have that the poll's reported results are close to the "true" figures; that is, the figures for the whole population... 2,900 years)	—

*Typographical error from original source material as per time table describing the spread of populations given in the same study.

Distribution

Average frequency of J Haplogroup as a whole is highest in the Near East (12%) followed by Europe (11%), Caucasus (8%) and North Africa (6%). Of the two main sub-groups, J1 takes up four-fifths of the total and is spread on the continent while J2 is more localised around the Mediterranean, Greece, Italy/Sardinia and Spain. In Pakistan, where West Eurasian lineages occur at frequencies of up to 50% in some ethno-linguistic groups, J1 averages around 5%, while J2 occurrence is very rare. Intriguingly, however, it is found amongst 9% of Kalash, a small ethnic community dwelling in the Hindu Kush mountains of Pakistan.

Within Europe, >2% frequency distribution of mtDNA J is as follows:

J* = Ireland — 12%, England-Wales — 11%, Scotland — 9%, Orkney — 8%, Germany — 7%, Russia (European) — 7%, Iceland — 7%, Austria-Switzerland — 5%, Finland-Estonia — 5%, Spain-Portugal — 4%, France-Italy — 3%
J1a = Austria-Switzerland — 3%
J1b1 = Scotland — 4%
J2 = France-Italy — 2%
J2a = Homogenously spread in Europe. Absent in the nations around the Caucasus. Not known to be found elsewhere.
J2b1 = Virtually absent in Europe. Found in diverse forms in the Near East.

Tree

This phylogenetic tree of haplogroup J subclades is based on the paper by Mannis van Oven and Manfred Kayser Updated comprehensive phylogenetic tree of global human mitochondrial DNA variation and subsequent published research.

mtDNA HG "J" P-tree
J J1 J1b J1b1 J1b1a J1b1a1 J1b1a2 J1b1b J1b1b1 J1b2 J1b3 J1c J1c1 J1c1b J1c1c J1c2 J1c2a J1c2b J1c2b1 J1c2b1a J1c3 J1c3a J1c3a1 J1c3b J1c3b1 J1c3c J1c4 J1c5 J1c5a J1c6 J1c7 J1c7a J1c8 J1d J1d1 J2 J2a J2a1 J2a1a J2a1a1 J2a1a1a J2a1a1b J2a2 J2a2a J2b J2b1 J2b1a J2b1a1 J2b1a2 J2b1a3 J2b1b

Genetic traits

It has been theorized that the uncoupling of oxidative phosphorylation related to SNPs which define mt-haplogroup J consequently produces higher body heat in the phenotype of mtDNA J individuals. This has been linked to selective pressure for the presence of the haplogroup in northern Europe, particularly Norway. J mtDNA has also been associated with HIV infected individuals displaying accelerated progression to AIDS and death. The T150C mutation, which is exclusive to but not definitive of, the J2 subclade of Haplogroup J may be part of a likely nuclearly controlled general machinery regarding the remodeling & replication of mtDNA. Controlling a remodeling which could accelerate mtDNA replication thus compensating for oxidative damage in mtDNA as well as functional deterioration occurring with old age related to it.

External links

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- Spread of Haplogroup J, from National Geographic
- Patterns of mtDNA Diversity in Europe, Lucia Simoni, 2000.

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- J mtDNA Yahoo Group File Download

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Origin

Distribution

Tree

Genetic traits

See also

External links