Haplogroup J (Y-DNA)

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In human genetics, Haplogroup J (previously known as HG9 or Eu9/Eu10) is a Y-chromosome DNA haplogroup. It is defined by the 12f2.1 genetic marker, or the equivalent M304 marker.

Haplogroup J is believed to have arisen between 10,000 and 15,000 years ago in the Near East. It is most closely related to Haplogroup I, as both Haplogroup I and Haplogroup J are descendants of Haplogroup IJ (S2, S22). Haplogroup IJ is in turn derived from Haplogroup F.

The Cohen Modal Haplotype falls in haplogroup J1, with respect to Cohens. (But the same CMH marker can sometimes be found in other haplogroups too, like J2.) The bulk of CMH is observed in J1 (53,0%) and J2 (43,2%) with a small portion falling outside haplogroup J (3,8%). Although you can have the CMH in either J1 or J2, it is the genetic signature in J1 that is considered the Jewish priestly signature.

1 Subdivisions
2 Subgroups
3 See also
4 References
5 External link

[edit] Subdivisions

It is subdivided into two haplogroups, haplogroup J2, defined by the M172 marker, and haplogroup J1, defined by the M267 marker.

Haplogroup J1 is most frequent in the Levant, mainly in the Bedouin tribes (62,5%) and Palestinian Arabs (38,4%), and is associated with the ancient Nabataeans. It entered Ethiopia in the Neolithic with the Neolithic revolution and spread of agriculture, where it is found mainly among Semitic speakers (Amhara 33,3%, but Oromo 3,8%). It spread later to North Africa in historic times (as identified by the motif YCAIIa22-YCAIIb22; Algerians 35,0%, Tunisians 30,1%), where it became something like a marker of the Arab expansion in the early medieval period(Semino et al. 2004). Researchers believe that marker DYS388=17 (Y DNA tests for STR - Short Tandem Repeater) is linked with the later expansion of Arabian tribes in the southern Levant and northern Africa (Di Giacomo et al. 2004). In Jewish populations overall, J1 constitutes 14.6% of the Ashkenazim results and 11.9% of the Sephardic results (Semino et al. 2004). Haplogroup J1 is considered "Semitic" in origin because is restricted almost completely to Middle Eastern populations (with very low frequencies in Italy and Greece). (Semino et al. 2004)

Haplogroup J2 is present especially in the Levant and Anatolia: in the Sephardim Jews (28,6%), Muslim Kurds (28,4%), Central Turks (27,9%), Georgians (26,7%), Lebanese (25%) and Ashkenazim Jews (23,2%). However, since it was one of the most important genetic markers of Anatolian neolithic agriculturalists, it is also very frequent in the Balkans (Greeks 20,6%, Albanians 19,6%) and in southern Italy (16,7-29,1%). Its frequency rapidly drops in the Carpathian basin (Croatians 6,2%, Hungarians 2,0%, Ukrainians 7,3%). The significant presence of J2 (J2b2+J2a) in India (18,6% in Dravidian upper castes, 14% in Aryan upper castes, 2% in tribes; Sengupta et al. 2006) must be of a very early date, because Indian J2 is not accompanied by its "loyal fellow-traveller" E3b1 that penetrated to the Near East from North Africa after the end of the Ice Age and is tightly bound with the spread of both J-subbranches since the neolithic era. The subclade J2a may however be of more recent Aryan origin, because it is limited to North-West India and its origin is bound with Anatolia, an area where, according to some opinions, Indo-European languages originated.

There are also some haplogroup J Y-chromosomes that belong to neither J1 nor J2, and are said to be in paragroup J*(xJ1,J2). This means that haplogroup J* includes all of J eXcept[sic] for J1 and J2.

[edit] Subgroups

The subclades of Haplogroup J with their defining mutation, according to the 2006 ISOGG tree:

J (12f2.1, M304, S6, S34, S35)
- J*
- J1 (M267)
  - J1*
  - J1a (M62)
  - J1b (M365)
  - J1c (M367, M368)
  - J1d (M369)
  - J1e (M390)
- J2 (M172)
  - J2*
  - J2a (M410)
    - J2a*
    - J2a1 (DYS413≤18)
      - J2a1*
      - J2a1a (M47, M322)
      - J2a1b (M67 (S51))
        
        J2a1b*
        
        J2a1b1 (M92, M260)
        
        J2a1b1*
        
        J2a1b1a (M327)
        
        J2a1b2 (M163, M166)
      - J2a1c (M68)
      - J2a1d (M137)
      - J2a1e (M158)
      - J2a1f (M289)
      - J2a1g (M318)
      - J2a1h (M319)
      - J2a1i (M339)
      - J2a1j (M419)
      - J2a1k (DYS445≤7)
    - J2a2 (M340)
  - J2b (M12, M314, M221)
    - J2b*
    - J2b1 (M102)
      - J2b1*
      - J2b1a (M241)
        
        J2b1a*
        
        J2b1a1 (M99)
        
        J2b1a2 (M280)
        
        J2b1a3 (M321)
      - J2b1b (M205)

[edit] See also

[edit] References

yJdb: the Y-haplogroup J database haplotypes of haplogroup J.

O. Semino et al.: Origin, Diffusion, and Differentiation of Y-Chromosome Haplogroups E and J: Inferences on the Neolithization of Europe and Later Migratory Events in the Mediterranean Area. American Journal of Human Genetics, 2004, p. 1023-1034