title: Human chromosomal polymorphism. III. Chromosomal Q polymorphism in Mongoloids of northern Asia.
abstract: Q-heterochromatin variants in seven autosomes (3, 4, 13-15, 21, 22) were studied in two Mongoloid populations of northern Asia (Chukchi and Khakass). Q-staining was obtained using propylquinacrine mustard. Of 132 Chukchi individuals aged 13 to 20 years, 124 had Q-polymorphic chromosomes, while eight (6.0%) had no bands with fluorescence levels 4 and 5. The mean number of Q variants was 2.2 per individual. Of the 120 Khakass individuals aged 14 to 17 years, 112 had Q-polymorphic chromosomes, while eight (6.7%) had no Q variants with fluorescence levels 4 and 5. The mean number of Q variants was 2.5 per individual. No differences were found in the frequency of Q variants between sexes in the two populations. There was complete agreement between the observed homo- and heteromorphic frequencies and those predicted by the law of Hardy-Weinberg. As the Mongoloid populations of northern Asia showed statistically significant homogeneity both in the frequency of Q variants and the distribution of homo- and heteromorphic variants, they were examined as a single group--that of northern Mongoloids. The following questions are discussed: (1) the possible selective value of chromosomal Q-heterochromatin material in the adaptation of human populations to certain extreme environmental factors, in particular to cold and hypoxia; (2) the intraracial heterogeneity of Asian Mongoloids; (3) the taxonomic value of chromosomal Q polymorphism in ethnic anthropology.
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People; D002871:Chromosome Banding; D002877:Chromosomes, Human; D002900:Chromosomes, Human, 1-3; D002901:Chromosomes, Human, 13-15; D002904:Chromosomes, Human, 21-22 and Y; D002905:Chromosomes, Human, 4-5; D005260:Female; D006570:Heterochromatin; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D012800:Siberia
chemical_list: D006570:Heterochromatin