Recent male-mediated gene flow over a linguistic barrier in Iberia, suggested by analysis of a Y-chromosomal DNA polymorphism.
We have examined the worldwide distribution of a Y-chromosomal base-substitution polymorphism, the T/C transition at SRY-2627, where the T allele defines haplogroup 22; sequencing of primate homologues shows that the ancestral state cannot be determined unambiguously but is probably the C allele. Of 1,191 human Y chromosomes analyzed, 33 belong to haplogroup 22. Twenty-nine come from Iberia, and the highest frequencies are in Basques (11%; n=117) and Catalans (22%; n=32). Microsatellite and minisatellite (MSY1) diversity analysis shows that non-Iberian haplogroup-22 chromosomes are not significantly different from Iberian ones. The simplest interpretation of these data is that haplogroup 22 arose in Iberia and that non-Iberian cases reflect Iberian emigrants. Several different methods were used to date the origin of the polymorphism: microsatellite data gave ages of 1,650, 2,700, 3,100, or 3,450 years, and MSY1 gave ages of 1,000, 2,300, or 2,650 years, although 95% confidence intervals on all of these figures are wide. The age of the split between Basque and Catalan haplogroup-22 chromosomes was calculated as only 20% of the age of the lineage as a whole. This study thus provides evidence for direct or indirect gene flow over the substantial linguistic barrier between the Indo-European and non-Indo-European-speaking populations of the Catalans and the Basques, during the past few thousand years.
Hurles
M E
ME
Department of Genetics, University of Leicester, University Road, Leicester, United Kingdom.
Veitia
R
R
Arroyo
E
E
Armenteros
M
M
Bertranpetit
J
J
Pérez-Lezaun
A
A
Bosch
E
E
Shlumukova
M
M
Cambon-Thomsen
A
A
McElreavey
K
K
López De Munain
A
A
Röhl
A
A
Wilson
I J
IJ
Singh
L
L
Pandya
A
A
Santos
F R
FR
Tyler-Smith
C
C
Jobling
M A
MA
D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000235:genetics; D005006:Ethnicity; D019143:Evolution, Molecular; D006239:Haplotypes; D006801:Humans; D007802:Language; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D051876:Sex-Determining Region Y Protein; D013030:Spain; D014157:Transcription Factors; D014998:Y Chromosome / Q000235:genetics*
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D051876:Sex-Determining Region Y Protein; D014157:Transcription Factors; C497745:SRY protein, human; C541744:Ybx1 protein, mouse