Haplogroup J (mtDNA)

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. [1]

Origins

Around 45,000 years before present, a mutation took place in the DNA of a woman who lived in the Caucasus region. 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.

Locale

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.

Distribution within Europe

Within Europe, >2% frequency distribution of mtDNA J is as follows [2]: 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. [3] J2b1 = Virtually absent in Europe. Found in diverse forms in the Near East. [4]

Coalescence times for the subclades of mitochondrial haplogroup J

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

See also

• Human mitochondrial genetics

External links

• J1 (& subclades) mt-Haplogroup project at FTDNA
• J2 (& 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" [7] [8]
• 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.