Gene geographic analysis of a subdivided population: The Adyge gene pool in the gene pool system of Caucasian ethnoses

A gene geographic analysis of the indigenous population of the Caucasian hi storical cultural province was carried out with a set of genetic markers ex tensively studied in the Adyges (39 alleles of 18 loci): ABO, ACP, C3, FY, GC, GLO, HP, KEL, LEW, MN, MNS, P, PGD, PGM1, RH-C, RH-D, RH-E, and TF. Gen etic information on 160 Caucasian populations was used (on average, 65 popu lations per locus). A synthetic map of the first principal component clearl y showed a division into two gene geographic provinces: Northern Caucasus a nd Transcaucasia. The component significantly differed across the Greater C aucasian Ridge. One of the major regions of extreme values corresponded to the Adyge region. A map of the second component revealed two poles, Northwe stern (the Adyges) and Caspian, in gene pool variation of the Caucasian pop ulation. The analysis of the maps and the space of principal components sho wed that the Adyge population is an important part of the Caucasian gene po ol. A map of genetic distance from all Caucasian populations to the Adyges showed that the north Caucasian populations (excluding the Ossetes) are the most genetically similar to the Adyges, while Georgians from the Kolkhida Valley and Azerbaijanians from the lowlands near the Caspian Sea and highla nd steppes are the most genetically remote from the Adyges. The genetic div ersity (G(ST) x 10(2)) of the entire Caucasian gene pool was studied. The a verage diversity of subpopulation within a Caucasian ethnos was G(S-E) = 0. 81, the diversity of ethnoses within a linguistic family was G(E-L) = 0.83, and the diversity of linguistic families was G(L-T) = 0.58. The race class ification of the Caucasian populations (G(S-E) = 0.81, G(S-R) = 0.80, G(R-T ) = 0.76) proved to be more genetically informative than the linguistic one . The major parameters of the Adyges (total diversity H-T = 0.364, heterozy gosity H-S = 0.361, and subpopulation diversity within the ethnos G(S-E) = 0.69) were similar to those averaged over the entire Caucasian population. A comparison with the same set of generic markers showed that the interethn ic diversity in the Caucasian region was lower than in the other north Eura sian regions (G(S-E) was 1.24 in the European region, 1.42 in the Ural regi on, 1.27 in Middle Asia, and 3.85 in Siberia).