The relationship between the Y chromosome size and the amount of autosomal Q-heterochromatin in human populations.

The relationship between the basic quantitative characteristics of the Q-heterochromatin (Q-HR) region variability of autosomes and of the Y chromosome in human populations was examined. A definite relationship between the mean number of Q-HR per individual, the distribution and frequencies of Q-HR on autosomes and the size of the Q-heterochromatin segment of the Y chromosome at the population level was shown to exist. The amount of autosomal Q-HR was lower in individuals with larger Q-heterochromatin segments on Y chromosomes, and vice versa. The hypothesis that the amount of chromosomal Q-HR in the genome of modern human populations may be under the control of natural selection, is discussed.

Assesment of q-heterochromatin in patients with acute mountain sikness / En pacientes con el mal de montaña agudo

El presente estudio se ha diseñado para determinar marcadores genéticos del posible desarrollo del mal de montaña agudo (MMA), para lo cual se ha evaluado el número y distribución de las regiones cromosomiales específicas, nominalmente, las regiones de heterocromatina-Q (Q-HR) en 34 sujetos que desarrollaron MMA después de ascender a 3600 metros sobre el nivel del mar (Eastern Pamir). Los controles fueron 36 sujetos sin signos de MMA. El análisis de Q-HR se realizó utilizando la tinción de mostaza de propil quinacrina de las preparaciones cromosomales obtenidas de los cultivos de linfocitos. A diferencia de los controles, los sujetos con MMA mostraron ciertas diferencias en la distribución de características cuantitativas de la Variabilidad cromosomal Q-HR; el número total de Q-HR en sujetos con MMA fue de 2.15 +/- 0.19 en tanto que en los cointroles fue de 1.06 +/- 0.14 (P menor que 0,001). Estos datos sugieren el rol de la predisposición hereditaria en el desarrollo del mal de montaña agudo.

Transferrin subtypes in some Eurasian and African populations.

Transferrin (TF) subtypes in blood serum were assessed by isoelectric focusing in 2,035 healthy unrelated individuals from populations in different regions of Eurasia and Africa. Considerable heterogeneity for TF subtypes was found between the populations studied. The data obtained were compared with those of other investigators.

Cerumen phenotypes in certain populations of Eurasia and Africa.

Cerumen polymorphism was studied in several populations of Eurasia and Africa. The frequencies of dry cerumen were shown to be high in Mongoloid populations and low among Europoids. Intermediate frequencies were found among peoples of subequatorial Africa. Special attention is paid to the potential for using this marker in population and anthropological studies.

Chromosomal Q-heterochromatin regions in the indigenous population of the northern part of West Siberia and in new migrants.

The variability of Q-heterochromatin regions (Q-HR) was studied in native residents of the northern part of West Siberia, viz Yakuts (n = 127), Selkups (n = 90) and Khants (n = 54), as well as in newcomers including oil-borers (n = 43) and children (n = 113) living permanently in this part of the USSR. The major quantitative characteristics of chromosomal Q-HR variability were shown to be very similar in oil-borers and natives, and this is considered to be the result of specific selection of individuals according to the amount of Q-HRs in their genome. The hypothesis on the possible selective value of chromosomal Q-HRs in human adaptation to extreme environmental conditions of the extreme north is discussed.

Chromosomal Q-heterochromatin regions in native highlanders of Pamir and Tien-Shan and in newcomers.

The variability of human chromosomal Q-heterochromatin regions (Q-HR) was studied in 385 newcomers well adapted to the extreme environmental conditions of Pamir and Tien-Shan, as well as in 284 representatives of the native population of these regions. Newcomers were found to represent a highly homogeneous group as regards all the quantitative characteristics of Q-HR variability, but at the same time they differed significantly from both native residents and individuals of similar nationality (Russians) living permanently at low altitude. Differences between these three groups in the amount of Q-HRs in their genome are discussed as evidence in favour of the hypothesis of the possible selective value of chromosomal Q-heterochromatin material in human adaptation to extreme environmental high-altitude conditions.

Human chromosomal polymorphism. VIII. Chromosomal Q polymorphism in the Yakut of Eastern Siberia.

Chromosomal Q polymorphism was studied in 157 adolescents of Yakut nationality (67 males and 90 females) living in Eastern Siberia, on the territory of the Yakut ASSR. Of the 157 subjects, 123 had chromosomal Q variants while 34 (21.7%) had no Q-heterochromatin bands with fluorescence levels 4 and 5. The mean number of Q variants per individual ranged from 0 to 5, with a mean of 1.64. No differences were observed in the frequency of Q variants between sexes. The observed homo- and heteromorph frequencies always agreed with those predicted by the law of Hardy-Weinberg. Of the 157 subjects, four (2.55%) had pericentric inversion of the Q-heterochromatin band in chromosome 3. The following topics are discussed: possible selective value of chromosomal Q-heterochromatin material in the adaptation of human populations to extreme environmental factors, in particular to cold; the taxonomic value of chromosomal Q polymorphism in ethnic anthropology.

Human chromosomal polymorphism. IX. Further data on the possible selective value of chromosomal Q-heterochromatin material.

Chromosomal Q-polymorphism was studied in 198 Kirghiz subjects (98 males and 100 females) from one high-altitude isolate located in the south-eastern part of Kirghizia. Small samples of mountaineers (N = 37) and volunteer subjects (N = 34) were also studied. The samples studied did not differ significantly from each other in the relative frequencies of chromosomal variants in 12 loci of seven Q-polymorphic autosomes. The mean number of Q variants per individual in the populations ranged from 1.3 to 2.0. No sex differences were found in the frequencies of Q variants. The observed homo- and heteromorphic frequencies agreed with those predicted by the law of Hardy-Weinberg. The possible selective value of chromosomal Q heterochromatin material in the adaptation of human populations to high-altitude climate is discussed.

Chromosome preparations of human whole blood lymphocytes: an improved technique.

A new modification of currently utilized methods of processing cell cultures of whole peripheral blood for obtaining chromosome preparations necessary for differential staining (Q, G and C) is proposed. After the usual hypotonic treatment of cultures, a 3%-5% aquaeous solution of glacial acetic acid is added to the cell suspension prior to fixation in order to completely destroy and wash out red cells, as well as for selective fixation of lymphocytes.

Human chromosomal polymorphism. VII. The distribution of chromosomal Q-polymorphic bands in different human populations.

The distribution of chromosomal Q-polymorphic bands was studied in different human populations. The populations studied showed no differences in the relative amount of Q bands in all the 12 polymorphic loci of seven autosomes, but interpopulation differences did exist in the absolute amount of Q bands in all the 12 potentially polymorphic loci of seven autosomes, these differences consisting of uniform increases or decreases in this absolute amount. Comparisons of the mean number of Q-heterochromatin bands with fluorescence levels 4 and 5 per individual showed a consistent prevalence of this quantitative parameter of chromosomal Q polymorphism in females as compared to males in all the national groups. It is suggested that there is some dosage compensation of chromosomal Q-heterochromatin material in females due to the absence of a chromosome in their genome, which is able to "compensate" for the large Q band in chromosome Y which is present only in the karyotype of males.

Human chromosomal polymorphism. VI. Chromosomal Q polymorphism in Turkmen of the Kara-Kum desert of Central Asia.

Chromosomal Q polymorphism was studied in 116 Turkmen, aboriginals of the Kara-Kum desert of Central Asia. Propylquinacrine mustard was used as fluorochrome. Of the 116 subjects aged 16-20 years, 109 (94.0%) were found to have Q-polymorphic variants, while seven (6.0%) showed complete absence of Q bands with fluorescence levels 4 and 5. There was a total of 351 polymorphic Q bands, 0-7 per individual, with a mean of 3.0 in the population. No differences between sexes were observed in the frequency of Q bands. The observed homo- and heteromorph frequencies proved to be in complete agreement with those predicted by the law of Hardy-Weinberg. Chromosome 3 with pericentric inversion of the Q-heterochromatin band was found in two (1.7%) of the 116 subjects. The following questions were examined: (1) the possible selective value of chromosomal Q-heterochromatin material in the adaptation of human populations to extreme environmental factors, in particular to the desert climate; (2) intraracial heterogeneity in Europoids of Eurasia; (3) the taxonomic value of Q polymorphism in ethnic anthropology.

Human chromosomal polymorphism. I. Chromosomal Q polymorphism in Mongoloid populations of Central Asia.

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.

Human chromosomal polymorphism. II. Chromsomal C polymorphism in Mongoloid populations of Central Asia.

C polymorphism of chromosomes 1, 9 and 16 was studied in 447 Mongoloids of Central Asia living under different ecological conditions; two highland (Kirghiz) and three steppe (Kazakh, Mongolian, and Dungan) populations. C band sizes were estimated according to the semiquantitative 5-level method of Patil and Lubs (1977). All the ethnic groups studied showed statistically significant homogeneity in the frequency of C variants. It is suggested that chromosomal C-heterochromatin material has no selective value in the process of human adaptation to extreme high-altitude factors.

Human chromosomal polymorphism. IV. Chromosomal Q polymorphism in Russians living in Kirghizia.

Chromosomal Q polymorphism was studied in 200 Russian individuals (94 females and 106 males) living in Kirghizia. Of the 200 individuals, 191 had chromosomal Q polymorphic variants, while nine (4.5%) had no Q bands with fluorescence levels 4 and 5. The mean number of Q variants per individual ranged from 0 to 7, with a mean of 2.9. There were no differences in the frequency of Q variants between sexes. The observed homo- and heteromorphic frequencies completely agreed with those predicted by the law of Hardy-Weinberg. Of the 200 individuals, 12 (6.0%) had pericentric inversion of the Q band in chromosome 3, one individual (0.5%) having a homomorphic form of this inversion. The possible selective value of chromosomal Q heterochromatin material in the adaptation of human populations to extreme environmental factors, in particular to cold, and the possible taxonomic value of inverted Q heterochromatin bands in chromosome 3 in ethnic anthropology, are discussed.

Human chromosomal polymorphism. V. Chromosomal Q polymorphism in African populations.

The distribution pattern of Q-heterochromatin variants in seven autosomes (3, 4, 13-15, 21, and 22) was studied in three aboriginal Negroid populations of Africa (Mozambique, Angola, and Ethiopia). It was shown that among African Negroids there are no individuals completely lacking Q-heterochromatin bands with fluorescence levels 4 and 5. The mean number of Q variants per individual was 3.47, 4.80, and 4.85 in the Ethiopian, Mozambique, and Angola populations, respectively. The observed homo- and heteromorphic frequencies always agreed with those predicted by the law of Hardy-Weinberg. The populations of tropical lowland Negroids (Mozambique and Angola) proved to be significantly homogeneous both in the frequency of Q variants and the mean number of these variants per individual, so they were examined as a single group. However, comparative analysis of highland (Ethiopians) and lowland Negroids revealed statistically significant differences. The following questions are discussed: (1) the possible selective value of chromosomal Q heterochromatin material in the adaptation of human populations to high-altitude climate; (2) the possible existence of intraracial heterogeneity in Negroids living in different ecological zones of Africa; (3) the possible taxonomic value of an inverted Q-heterochromatin band in chromosome 3 in ethnic anthropology.

Human chromosomal polymorphism. III. Chromosomal Q polymorphism in Mongoloids of northern Asia.

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.

[Individuality of human chromosome polymorphism revealed by Q-staining]. / Individual'nost' polimorfizma khromosom cheloveka, vyiavliaemogo po Q-okraske.

The G-polymorphism of metaphase chromosomes of peripheral human lymphocytes and its inheritance in 32 families (268 persons) and 315 unrelated persons after G-staining has been studied. The site of Q-heterochromatine, its size and the length of secondary constrictions were accepted as morphological signs of Q-polymorphic variants of chromosomes. All the three chromosome signs are shown to be inherited according to codominant type and are characteristic features of each separate chromosome. No identical patterns of Q-polymorphic chromosome variants are found among all the persons studied, except the monozygotic twins. According to the data obtained, the question of individualization of each chromosome in the karyotype (3, 4, 13--15, 21, 22) and of each personal individuality in relation to Q-polymorphism is discussed.

[Ability to test phenylthiocarbamide (PTC-test) among the population of Kirghizia]. / Izuchenie sposobnosti oshchushchat' vkus feniltiokarbamida (PTC-test) sredi naseleniia, prozhivaiushchego v Kirgizii.

The distribution of the taste sensitivity to phenylthiocarbamide (PTC) among 320 Kirghiz boys, 320 Kirghiz girls, 45 Russian boys and 200 Russian girls was studied. The measurements of taste sensitivity to PTC was carried out by the standard method with a scale of PTC dilution to 29.