[Rare variants of blood proteins in human populations]. / Redkie varianty belkov krovi v populiatsiiakh cheloveka.

Rare variants of blood proteins occur, due to mutations (mutant alleles) in monomorphic loci encoding various proteins. A number of authors studied the distribution of these variants in human populations using the method of electrophoresis. The population of USA, South America, Japan, Europe was analysed. 1334 rare variants (1.0.10(-3)) were discovered out of 1,329,558 alleles (test locus in 664,779 individuals). 7 mutant alleles (3.6.10(-6)) were found among 1,957,305 alleles. The low frequency of occurrence of mutations in the loci encoding rare blood protein variants, when testing the speed of mutagenicity and its alteration, necessitates electrophoresis of blood proteins to be done in large scales. A method was proposed, based on accounting rare variants in children with congenital disorders, which are supposed to have a heavy load of mutations. The data collected demonstrated that the majority of rare variants in a given generation were obtained from parents. Accumulation of rare protein variants at low concentrations, as neutral alleles, in conditions of low mutation frequency in monomorphic loci takes place in the population. Comparison of frequencies of rare variants among healthy newborns and the children with congenital disorders revealed their identity (1.0.10(-3)), as compared to 1.05.10(-3)). Simplification of the method for scoring mutations judging by rare blood protein variants, which is necessary for monitoring for gene mutations in human populations, stimulates development of novel approaches.

[A.S. Serebrovskii's experimental studies on induced mutagenesis]. / Eksperimental'nye issledovaniia A.S. Serebrovskogo po indutsirovannomu mutagenezu.

The paper is devoted to A.S. Serebrovskii's studies on induced mutagenesis. His first publication on X-ray induction of mutations in Drosophila appeared in 1928; this became a classical work and entered the golden fund of modern radiation genetics. Investigations of the scientists in the A.S. Serebrovskii's laboratory as will as his own works on the analysis of radiation mutations at the achaete-scute complex have led to the development of the teaching about gene subdivision and made it possible to draw up a linear array of a gene from elementary subgenes, which have laid down the foundations of the modern molecular-genetic theory of gene.

[Use of the micronucleus test for assessing the ecological situation in regions of the Astrakhan district]. / Ispol'zovanie mikroiadernogo testa dlia otsenki ékologicheskoi obstanovki v raionakh astrakhanskoi oblasti.

The effect of industrial and agricultural contamination of the environment on the formation of micronuclei in peripheral blood cells of the lake frog Rana ridibunda P. was studied. Simultaneously, the influence of mutagenic contaminants on the human gene pool in Astrakhan' and Astrakhan' oblast' was analyzed. Frogs were trapped in three raions of Astrakhan' oblast': the villages of Trudfront and Verkhnii Buzan and Oblivnoi Island. Peripheral blood smears were prepared and cells with micronuclei and nuclear material were analyzed. Cells with micronuclei were 94.5 times more abundant in frogs from ecologically unfavorable Oblivnoi Island than in animals from Trudfront and 1.2 times more plentiful than in frogs from Verkhnii Buzan.

[Mutagenicity of drinking water in various districts of Moscow]. / Issledovanie mutagennosti pit'evoi vody iz raznykh g. Moskvy.

The mutagenicity of the drinking water from 16 districts of Moscow was investigated by analyzing of chromosome aberrations induced in cells of Crepis capilaris seeds used as a plant test system. Cytogenetic analysis revealed mutagenic activity in drinking water samples from four administrative regions, namely the Biryulevo-Zapadnoe district of Southern region (2.4%), Obruchevskii district of the Southwestern region (1.61%), Severnoe Tushino district of the Northwestern region (1.45%), and Perovo district of the Western region (1.18%). The frequency of chromosome aberrations found was significantly higher than in the spontaneous control (0.37%). Mutagenic activity was not detected in water samples taken from the Moscow oblast and from four open reservoirs.

[Variability and hereditability of neurodynamic and psychodynamic parameters in human populations]. / Izmenchivost' i nasleduemost' neirodinamicheskikh i psikhodina-micheskikh parametrov v populiatsiiakh cheloveka.

The authors elaborate the population-genetic approach to study the genetic basis of individual psychological differences. Psychodynamic parameters characterized by a more complex organization tend to be more phenotypically variable and less hereditable, as compared with parameters of lower organization levels. The results obtained are interpreted in relation to the genetic and social structure of populations.

[Cystamine and the chromosome vesting phenomenon]. / Tsistamin i iavlenie nadetosti khromosom

The effect of radioprotector cystamine on structural chromosome mutations induced in Crepis capillaris cells by gamma-rays 137Cs is studied. Cystamine at the concentration of 0,1% causes a two-fold decrease in the frequency of structural mutations. In the "vesting" phenomenon of ring chromosomes, under the same experimental conditions, it also leads to a two-fold decrease in the frequency of exchanges, in relation to the frequency of fragment units in the initial stage, by repair of normal chromosome structure. Cystamine provides protection in structural mutagenesis at the moment of realization of primary mutagenic changes into mutations due to enzyme ligazing chromosome fragments.

[Heritability of neurodynamics and psychodynamics in human populations]. / Nasleduemost' neirodinamiki i psikhodinamiki v populiatsiiakh cheloveka.

A component analysis of human neurodynamic and psychodynamic characters in the norm was carried out in 8 human populations characterized by different degrees of isolation and ethnic origin. An increase in phenotypic variability and a decrease in heritability with increasing complexity of organization of the characters under study were demonstrated for all these populations. The additive effect plays the major role in genetic determination of neurodynamic and psychodynamic characters studied. For a number of neurodynamic parameters the effect of intralocus dominance indicative of the oligogenic determination system was observed. Data in favour of real contribution of the factors linked to X-chromosome were obtained for simple sensomotor reactions.

[Population genetics of Dagestan highlanders]. / Populiatsionnaia genetika gortsev Dagestana.

Subdivision of some isolates and heterogenic populations in Daghestan is analysed by human gene and phen frequencies. Comparative population study of phenotypic variability of quantitative characters (anthropometric, neurodynamic and psychodynamic) is carried out. Common hierarchy of variability for all populations as well as an effect of inbreeding and panmixis on variability of the above-mentioned quantitative characters in different populations is demonstrated.

Gene mutations (de novo) found in electrophoretic studies of blood protein of infants with anomalous development.

Twelve proteins of enzymic and nonenzymic nature in blood samples of infants that deviate from the average population in physical development (50 premature and 177 full-term infants with rough and multiple developmental defects) were studied by electrophoresis in polyacrylamide and starch gels. The control group consisted of 500 normal newborns. In infants with developmental disorders, the frequency of rare electrophoretic protein variants was found to be about one order of magnitude higher than in the control. It has been shown for at least five cases that such variants are de novo mutations. According to these data the mutation rate is approximately 2 x 10(-3) per locus per generation for the group selected and approximately 6 x 10(-5) for the total population. Despite the fact that further specification of the estimations found is required, we consider the results obtained as evidence in favor of the efficiency of the earlier substantiated monitoring model of gene mutations in the human population [Dubinin, N.P. & Altukhov, Yu. P. (1977) in Genetic Consequences of Environmental Pollution, ed. Dubinin, N.P. (Mysl, Moscow), pp. 14-45]. This approach, which infers electrophoretic screening of blood proteins in a specially selected group of newborns, makes it possible to reduce the size of samples needed for statistically reliable estimations of the alteration of mutation rate.

Gravity, weightlessness and the genetic structures of organisms.

The whole evolution of life on earth has proceeded under the action of earth's gravity which must have influenced the structure and function of organisms. During space flights organisms are exposed to the entirely new condition of weightlessness, and to variations in gravity that produce various changes. Current flight data suggest that organisms most often respond to weightlessness by disturbances in physiological function, which are reversible after the brief exposures that have at present been possible. Only longer space flights will show whether these changes will be compensated, or will lead to alterations in the more important systems of organisms including their hereditary properties. There is evidence that weightlessness has a direct effect on genetic properties. Thus, in microspores of Tradescantia abnormal mitoses (that were not observed in the ground-based control) were recorded to an extent of 3%. The numerous changes in various vital systems suggest that for terrestrial organisms weightlessness is a factor which, if administered for a long time, may bring about serious disturbances in their activities and heredity. The higher the evolutionary position of the organism, the more pronounced the effect is likely to be.

The phenomenon of "vesting" in ring chromosomes and its role in the mutation theory and understanding of the mechanism of crossing-over.

After X-ray irradiation of Crepis capillaris dry seeds the authors detected, in addition to usual patterns of chromosome mutations, a new phenomenon of normal rod-shaped chromosomes being "vested," or encircled, by ring chromosomes. An analysis of the phenomena has demonstrated that the ring-chromosome production is connected with an X-ray-induced formation of a rigid loop by cross-links of different chromosome segments. The repair mechanism seems to cut DNA strands into three fragments at the cross-link site. When the fragment ends brought close together assume a definite position, the middle fragment forms a ring; the rejoined terminal fragments are within this ring which thus vests the chromosome. After DNA synthesis, two sister chromatids are vested by two sister rings. The appearance of different "vesting" patterns is associated with the mitotic crossing-over between sister ring chromatids. At this moment the internal chromatids appear to be capable of slipping out in different combinations from the rings vesting them. It has been shown that the DNA strands are cut into fragments during both the production of chromosome rearrangements and mitotic crossing-over. Due to the effect of chromosome repair cutting, chromosome rearrangements may result from exchange (contact of exchanging chromosomes in a cross-link site) and fragmentation mechanisms when DNA molecules are cut without cross-links or other mechanism assuring contact between different chromosome loci.