August 26, 2010

More structure in haplogroup R1b (Cruciani et al. 2010)

The stack of exciting papers to read keeps growing. Good things come in pairs for R1b folk.

Forensic Science International: Genetics doi:10.1016/j.fsigen.2010.07.006

Strong intra- and inter-continental differentiation revealed by Y chromosome SNPs M269, U106 and U152

Fulvio Cruciani et al.

More than 2700 unrelated individuals from Europe, northern Africa and western Asia were analyzed for the marker M269, which defines the Y chromosome haplogroup R1b1b2. A total of 593 subjects belonging to this haplogroup were identified and further analyzed for two SNPs, U106 and U152, which define haplogroups R1b1b2g and R1b1b2h, respectively. These haplogroups showed quite different frequency distribution patterns within Europe, with frequency peaks in northern Europe (R1b1b2g) and northern Italy/France (R1b1b2h).



Didier said...

L21 badly missing....

David said...

Looks like lack of data samples from The Netherlands, Norway, and Great Britain cause them to present a distribution map for R-U106 that presents a simplistic view compared to Myres (2010).

aargiedude said...

Between the Myres and Cruciani studies, North Italy was found to have 45 U152 out of 78 R1b1b2 (equal to 58% of their R1b1b2). From other studies, mainly yhrd, I estimate North Italy's R1b1b2 at exactly 50%. This results in North Italy having 29% U152 out of their total y-dna.

North Italy's neighbors to the north, west, and south have the 2nd highest frequencies of U152 in Europe, but they're all much lower than North Italy's. Switzerland has 18% U152 (n=175), southeast France has 17% U152 (n=367), and central Italy has 18% U152 (n=262).

On the other hand, North Italy's eastern neighbor, Slovenia, has 5% U152 (n=205).

From central Italy's 18% it then descends to 10% in south Italy, and it remains at 10% in Sicily. It's hard to calculate any other region in France besides the southeast, so as a proxy I'll use northeast Spain. From southeast France's 18%, the frequency descends to 10% in northeast Spain. And from Switzerland's 18% it then drops to 10% in west and south Germany.

Corsica has a whopping 32% U152 but with a very small sample size of just 28. Most of their R1b1b2 belongs to U152. Across Italy, even in Sicily and Sardinia, between 50% and 60% of the R1b1b2 belongs to U152. Instead, in France, only 25% of their R1b1b2 belongs to U152, including southeast France, where it's exactly 25%. So this is yet another component of Corsica's y-dna that points to an Italian origin for their people. Everything else about their y-dna also previously indicated an origin from Italy, preferably from the part of Italy closest to Corsica: central Italy.

There's no doubt about it, U152 is centered in North Italy. It doesn't share the throne with any neighboring region, it's North Italian-centric. Imagine a 4-sided pyramid with 3 sides sloping down and the eastern side imploded.

aargiedude said...

Oh, and I forgot to mention the curious case of North Africa's U152. North Africa has a unique R1b1b2 clade that seems to be specific to their region, from Morocco to Tunisia. It has an unusual modal haplotype, including a very rare .2 mutation in 385a/b (not to be confused with R1b1* in sub-Saharan Africa, which has a clade that also has a .2 mutation in 385a/b). It seems to have a cousin clade in Europe which also has the .2 mutation, and one of these European samples, Bricker, has tested U152+. So there's a very good chance that North Africa's clade is also U152.

The clade is 1% of North Africa's y-dna, with another 2% being "ht15" (L11/P312/U106), and another 1% in "ht35" (M269+ L23-). The clade, to top it off, is more common in Tunisia (pointing to an Italian origin) than in Morocco.

Sorry for double posting, second time today.