Haplogroup J (mtDNA)

Haplogroup J
Possible time of origin	45000 years before present
Possible place of origin	Western Asia
Ancestor	JT
Descendants	J1, J2
Defining mutations	295 489 10398 12612 13708 16069

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.

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’) is associated with the spread of farming and herding in Europe during the Neolithic Era (8,000-10,000 yrs ago). All other West Eurasian-origin groups (H, V, U, K, W, I, X) were previously given to hunting and gathering.

Coalescence times for the subclades of mitochondrial haplogroup J

Subclade	European coalescence time	Near East coalescence time
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.

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. However certain haplotypes of J2 are distinct to, and show a marked presence in, Scandinavia & the British isles. 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.

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 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.

See also

• Genealogical DNA test
• Genetic Genealogy
• Human mitochondrial genetics
• Population Genetics

Phylogenetic 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

External links

• General
  • Ian Logan's Mitochondrial DNA Site
  • Mannis van Oven's Phylotree
• Haplogroup J
  • Jim Logan's 2009 mt-Haplogroup J tree of subclades and branches by mutation
  • A Comprehensive Analysis of mtDNA Haplogroup J (Jim Logan. September, 2008)
  • A Refined Phylogeny for mtDNA Haplogroup J
  • Map of mtHaplogroup J. (Captions in Russian/Cyrillic)
  • J (& subclades) mt-Haplogroup project at FTDNA
  • mt Haplogroup J & Longevity; Article mentioning "frequency of the J haplogroup was notably higher in centenarians than in younger individuals" **[1] [2]
  • Spread of Haplogroup J, from National Geographic
  • Patterns of mtDNA Diversity in Europe, Lucia Simoni, 2000.
  • Human Mitochondrial Haplogroup J in Europe and Near East, Piia Serk, 2004.
  • J mtDNA Yahoo Group File Download