title: Human chromosomal polymorphism. I. Chromosomal Q polymorphism in Mongoloid populations of Central Asia.
abstract: A comparative study of frequencies and types of Q-polymorphic variants in seven autosome pairs (3, 4, 13-15, 21, and 22) was performed in three steppe Mongoloid populations of Central Asia (Kazakhs, Dunghans, Mongolians) and three highland Kirghiz populations of Pamir and Tien-Shan. The three steppe Mongoloid populations showed statistically significant homogeneity both in the frequency of Q-polymorphic variants and the distribution of homo- and heteromorphs, with complete agreement of observed frequencies with those theoretically predicted by the law of Hardy-Weinberg. Similar homogeneity was revealed in the three highland Kirghiz populations of Pamir and Tien-Shan. However, comparative analysis of highland and steppe Mongoloids revealed significant differences in the following variables: (1) mean number of Q variants per individual, 2.50 and 3.49 in the highland and steppe populations, respectively; (2) frequency of Q variants in 7 of the 12 autosomes studied; and (3) distribution of homo- and heteromorphs in four autosomal pairs (13-15, 21), with a preponderance of individuals with increased hemomorph (-/-) frequency in highlanders. The following questions are discussed: (1) the possible selective value of chromosomal Q-heterochromatin material in the adaptation of human populations to extreme environmental factors, in particular to the high-altitude environment of  Pamir and Tien-Shan; (2) the existence of intraracial heterogeneity in Mongoloids living in different ecological zones; and (3) the possible taxonomic value of Q-variant inversion in chromosome 3.
mesh_terms: D000293:Adolescent; D000531:Altitude; D044466:Asian People; D002871:Chromosome Banding; D002900:Chromosomes, Human, 1-3; D002901:Chromosomes, Human, 13-15; D002904:Chromosomes, Human, 21-22 and Y; D002905:Chromosomes, Human, 4-5; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation; D006570:Heterochromatin / Q000032:analysis*; D006801:Humans; D007623:Kazakhstan / Q000208:ethnology; D007707:Kyrgyzstan / Q000208:ethnology; D008297:Male; D011110:Polymorphism, Genetic; D011796:Quinacrine; D012641:Selection, Genetic
chemical_list: D006570:Heterochromatin; D011796:Quinacrine