Haplogroup J (mtDNA)

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Haplogroup J
Possible time of origin 45,000 years before present
Possible place of origin Caucasus, Eurasia
Ancestor JT
Descendants J1, J2
Defining mutations 295 489 10398 12612 13708 16069[1]

In human mitochondrial genetics, Haplogroup J is a human mitochondrial DNA (mtDNA) haplogroup. Haplogroup J derives from the haplogroup JT, which also gave rise to Haplogroup T. In his popular book The Seven Daughters of Eve, Bryan Sykes named the originator of this mtDNA haplogroup Jasmine. Within the field of medical genetics, certain polymorphisms specific to haplogroup J have been associated with Leber's hereditary optic neuropathy.[2]

Origin

Around 45,000 years before present, a mutation took place in the DNA of a woman who lived in the Near East or Caucasus. 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’) MtDNA J & T colonised Europe from the Near East in the late Paleolithic & Mesolithic.

Coalescence time estimates for the subclades of mitochondrial haplogroup J
Subclade European coalescence time[2] Near East coalescence time[2]
J1a1 27,300 years (± 8,000 years) 17,700 years (± 2,500 years)
J1a2 7,700 years (± 3,500 years) —
J1b 5,000 years (± 2,200 years) 23,300 years (± 4,300 years)
J2a 19,200 years(± 6,900 years) —
J2b1 — 15,000 years (± 5000 years)
J2b2 161,600* years (± 8,100 years) 16,000 years (± 5,700 years)
J2b3 5,800 years (± 2,900 years) —

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

However, any statements concerning the geographic origin of this or any other haplogroup are highly speculative and considered by most population geneticists to be 'story telling' and outside the domain of science[citation needed] . Furthermore, inferring close associations between a haplogroup and a specific archaeological culture can be equally problematic.[by whom?]

Distribution

Haplogroup J is found in approximately 12% of native Europeans.[3][4]

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. There is a high (19%) incidence of J1 haplogroup among the Polish Roma ethnic group which is ascribed to the founder effect.[5] 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. It is also found amongst 9% of Kalash.[6]

Within Europe, >2% frequency distribution of mtDNA J is as follows:[7]

  • 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.[2]
  • J2b1 = Virtually absent in Europe. Found in diverse forms in the Near East.[2]
  • J2b1a = Found in Western Europe and Russia.[2]

Subclades

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[1] and subsequent published research.

Genetic traits

It has been theorized[by whom?] 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.[8] Individuals from haplogroups Uk, J1c and J2 were found to be more susceptible to Leber's hereditary optic neuropathy because they have reduced oxidative phosphorylation capacity, which results in part from lower mtDNA levels.[9] J mtDNA has also been associated with HIV infected individuals displaying accelerated progression to AIDS and death.[10] 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.[11] Haplogroup J was found to be a protective factor against ischemic cardiomyopathy.[12] It was also found that Haplogroup J was a protective factor among osteoarthritis patients from Spain[13] but not from UK,[14] and this was hypothesized to be due to a different genetic composition (polymorphisms) of the Haplogroup J in both populations. A study involving patients of European and West Asian origin or descent showed that individuals classified as haplogroup J or K demonstrated a significant decrease in risk of Parkinson's disease versus individuals carrying the most common haplogroup, H. [15]

Popular culture

See also

Evolutionary tree of human mitochondrial DNA (mtDNA) haplogroups
  Mitochondrial Eve (L)    
L0 L1–6
L1 L2 L3   L4 L5 L6
  M   N  
CZ D E G Q   O A S   R   I W X Y
C Z B F R0   pre-JT P  U
HV JT K
H V J T

References

  1. ↑ 1.0 1.1 Lua error in package.lua at line 80: module 'strict' not found.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Piia Serk, Human Mitochondrial DNA Haplogroup J in Europe and Near East, Thesis, Tartu 2004
  3. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  4. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  5. ↑ B.A. Malyarchuk, T. Grzybowski, M.V. Derenko, J. Czarny, and D. Miścicka-Śliwka, Mitochondrial DNA diversity in the Polish Roma, Annals of Human Genetics, vol. 70 (2006), pp. 195-206.
  6. ↑ Lluís Quintana-Murci, Raphaëlle Chaix, R. Spencer Wells, Doron M. Behar, Hamid Sayar, Rosaria Scozzari, Chiara Rengo, Nadia Al-Zahery, Ornella Semino, A. Silvana Santachiara-Benerecetti, Alfredo Coppa, Qasim Ayub, Aisha Mohyuddin, Chris Tyler-Smith, S. Qasim Mehdi, Antonio Torroni, and Ken McElreavey, Where west meets east: the complex mtDNA landscape of the southwest and Central Asian corridor, American Journal of Human Genetics, vol. 74 (2004), pp. 827–845.
  7. ↑ Lucia Simoni, Francesc Calafell, Davide Pettener, Jaume Bertranpetit, and Guido Barbujani, Geographic Patterns of mtDNA Diversity in Europe, American Journal of Human Genetics, vol. 66 (2000), pp. 262–278.
  8. ↑ Different genetic components in the Norwegian population revealed by the analysis of mtDNA & Y chromosome polymorphisms
  9. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  10. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  11. ↑ A Comprehensive Analysis of mtDNA Haplogroup J (Jim Logan. September, 2008)
  12. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  13. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  14. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  15. ↑ Lua error in package.lua at line 80: module 'strict' not found.
  16. ↑ 23andMe
  17. ↑ http://quo.mx/2012/05/30/plus/la-genetica-tras-la-belleza-de-ximena
  18. ↑ Lua error in package.lua at line 80: module 'strict' not found.

External links

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