[The alterations in profiles of RAPD- and of ISSR-markers in progeny of the single gamma-irradiated mice of BALB/c strain].

Molecular-genetic effects in the offspring of BALB/c male mice exposed to single radiation doses of 1, 2 and 3 Gy were studied. Induced genetic variability was studied using such methods as assessment of variation RAPD- and ISSR-profiles. Comparative analysis of genetic radiosensitivity of stem spermatogonia and of spermatids is presented in the work. The frequency of changes in the patterns of the offsprings of irradiated mice was significantly different from the analogous parameters in the offsprings of the control group already at a dose of 1 Gy. Comparative analysis of genetic radiosensitivity at different stages of spermatogenesis revealed the similar sensitivity of spermatogonia and of spermatids at 1 and 3 Gy and a higer sensitivity of spematogonia at 2 Gy.

[The influence of chronic and of acute irradiation on the polymorphism of RAPD-markers in offspring for irradiated mice].

On mice lines BALB/c and CBA/lac was performed the study of molecular-genetics effects in mice progeny after the chronic (dose rate -0.0017 Gy/day, total dose -0.36 Gy) and acute (dose range 1-3 Gy) exposure of y-radiation on the parents. For variability analysis was used technique of amplification DNA with series of random primers (RAPD-assay). Random primers were used as single primer and in mixture of ones. In this work were held the comparative analysis of the genetic radiosensitivity for stem spermatogonia and spermatides. After the acute exposure the dose dependence for levels of polymorphism of RAPD-markers were obtained. After the chronic irradiation, significant differences from control group were obtained only by use primers mixture M1. Comparative analysis of the genetic radiosensitivity of different stages of mice spermatogenesis are display is similar sensitivity of stem spermatogonia and spermatides after doses of irradiation 1 Gy and 3 Gy. Indicated that after irradiation by dose 2 Gy, spermatogonia are more sensitivity than spermatides.

[Genetic consequences of an increased radiation background at mouse-like rodents].

The frequency of genetic disturbances in germ-line and in somatic cells was studied in animals caught in radionuclide-cotaminated areas within the 30-km Chernobyl NPP zone as well as in model experiments in laboratory mice exposed to chronic external gamma-radiation or to the internal action of incorporated radionuclides (131I, 137Cs, 238Pu). The results of genetic and of cytologic analysis of germ-line and somatic cells in the caught or exposed house mice and in laboratory mice after incorporation of radionuclides are presented. An estimation of relative genetic efficiency of the most harmful radionuclides was made.

[Comparison of three inbred lines of mice by overall and genetic radiosensitivity]. / Sravnenie trekh inbrednykh linii myshei po obshchei i geneticheskoi radiochuvstvitel'nosti.

The radiosensitivities of three mouse strains (BALB/cLacY, C3H/SnY, and 101/HY) have been compared using the following parameters: survival after irradiation at a dose of 6-7 Gy, chromosome aberration frequency in bone marrow cells after irradiation at a dose of 1.5 Gy, and the change in testis weight and frequency of abnormal sperm heads (ASHs) after irradiation at doses from 0.5 to 4 Gy. Strain BALB/c is the most radiosensitive with respect to the survival and chromosome aberration frequency in the bone marrow but the most resistant with respect to the change in testis weight and the frequency of abnormal sperm heads. Strain 101/HY was the most resistant with respect to survival and chromosome aberration frequency in bone marrow after irradiation but the most radiosensitive with respect to testis damage.

[Effect of indralin on genetic disruption induced by radiation in mice]. / Vliianie indralina na geneticheskie narusheniia, indutsirovannye radiatsiei u myshei.

The effect of indralin on frequency of mutations induced by radiation in germ cells, reciprocal translocations, and testicle weight of male mice. The level of protective effect against genetic damage varied depending on the radiation dose and spermatogenesis stage. The values of the defense coefficient ranged from 0.16 to 0.35.

[Estimation of genetic effects of chronic exposure to low-dose rate gamma-radiation by cytogenetic methods and DNA-comet assay]. / Otsenka geneticheskikh éffektov khronicheskogo vozdeistviia nizkointensivnogo gamma-izlucheniia tsitogeneticheskimi metodami i metodom DNK-komet.

The study of genetic effects in CBA/lac mice exposed for 1 year to constant low dose-rate gamma-radiation at a dose-rate 63 cGy/year has been carried out. We have shown the significant increase in the DNA breaks' level in spleen lymphocytes by comet-assay beginning from the total absorbed dose of 20 cGy. It is possible that the DNA breaks' level increase resulted from the structural rearrangement of chromatin or induction of lymphocyte proliferation. The results obtained by micronucleus test have proved that the mutagenic effect of chronic low dose-rate gamma-radiation depends on cell type and respectively on cell proliferation rate, cell differentiation, etc. So, by the end of experiment the significant increase in the frequency of PCE with micronuclei (MN) was observed. However, in contrast, the frequency of NCE with MN was not increased. No significant increase in the percent of lung cells with MN was registered.

[The estimation of molecular and cytogenetic effects in mice exposed to chronic low dose gamma-radiation]. / Otsenka molekuliarnykh i tsitogeneticheskukh éffektov khronicheskogo vozdeistviia nizkointensivnogo gamma-izlucheniia u myshei.

Molecular and cytogenetic parameters were estimated in male CBA/lac mice exposed to chronic low dose-rate gamma-radiation (62 cGy/year) for 40, 80, 120, 210, and 365 days. After 40 days of exposure (6.7 cGy), spleen lymphocyte susceptibility to hydrogen peroxide was shown to increase. However, beginning from the day 120 of the treatment (20.4 cGy), the opposite effect was observed. An increase in number of the DNA-protein crosslinks was recorded in spleen lymphocytes only on day 40 of the experiment. The number of DNA breaks increased significantly beginning from day 120 of the experiment, as shown by the DNA-comet method. On the day 210 of irradiation, the frequency of abnormal sperm heads in the mice significantly increased. The number of normochromatic micronucleated erythrocytes of the peripheral blood remained unchanged.

[Effects of para-aminobenzoic acid on radiosensitivity of mice of different strains]. / Vliianie paraaminobenzoinoi kisloty na radiochuvstvitel'nost' myshei raznykh linii.

The aim of the work was to study the possible protective effect of para-aminobenzoic acid (PABA) on the radiation lethality in mice of three inbred lines (BALB/cLacY, C3H/HeY, 101/Hy), stock YT1 and hybrids (C3H/He x 101/H)F1. The PABA solution was given to the mice intraperitoneally in single doses of 10, 50 and 100 mg/kg 40-50 min prior to irradiation with doses of 6 to 8 Gy depending on the line and sex of mice. The used doses of gamma-radiation were roughly LD75/30. The radioprotective effect of PABA was observed in all variants of the experiment but it was relatively low. The protection coefficient varied from 0 to 0.45. The protective effect depended on the line and sex of mice and on the dose of the injected substance.

[The effect of chronic exposure to cadmium and gamma radiation at low doses on the genetic structures in mice]. / Vliianie khronicheskogo vozdeistviia kadmiia i gamma-izlucheniia v malykh dozakh na geneticheskie struktury myshei.

The DNA-protein cross-links (DPC) in mouse thymocytes and spleen lymphocytes, the number of abnormal sperm heads (ASH) and the number of micronuclei (MN) in normochromatic erythrocytes (NCE) of peripheral blood were studied in mice exposed to long-term low-intensity gamma radiation (0.072 cGy/days) and/or cadmium with drinking water (0.01 mg Cd2+/l) for 20, 40 and 80 days. The dependence of DPC level on the total dose (exposure time) of gamma radiation and/or cadmium is nonlinear. The maximal level of DPC in cells of lymphoid organs upon exposure to gamma radiation or cadmium was recorded on the 40-th day, and under combined exposure on the 20-th day of the experiment. The long-term exposure to cadmium or gamma radiation causes an increase in the ASH frequency. The increase in frequencies of MN in NCE and reciprocal translocations in spermatocytes was not found.

[Mutagenesis in Muridae from regions with increased radiation level]. / Mutatsionnyi protsess u myshevidnykh gryzunov, obitaiushchikh v raionakh s povyshennym fonom radiatsii.

Genetic monitoring of wild populations of mouse-like rodents has been carried out since 1992 in areas with the increased radioactivity in the south of the Bryansk region. The radioactive background ranged from 0.20 to 2.20 mkGy/h. Over 400 rodents of different species have been examined. Bank vole constituted more than a half of the examined animals. The genetic effect of radiation was estimated by the frequency of micronuclei in normochromatic erythrocytes of peripheral blood and by the frequency of abnormal sperm heads. In house mice the frequency of reciprocal translocations and the level of embryo mortality were studied in the progeny of the caught male mice mated with intact laboratory females. The data obtained demonstrate that the yield of induced genetic disorders by all tests was relatively low and only in a few cases the frequency of disturbances tended to increase with an increase in the level of radionuclide contamination in the examined areas.

[The genetic monitoring of the house mouse population from areas contaminated by radionuclides as a result of the accident at the Chernobyl Atomic Electric Power Station]. / Geneticheskii monitoring populiatsii domovykh myshei iz raionov, zagriaznennykh radionuklidami v rezul'tate avarii na Chernobyl'skoi AES.

In 1986-1994, genetic effects of radiation on males of wild mice caught in areas of radioactive contamination after the Chernobyl reactor accident were studied. The gamma-radiation dose rates on the soil surface in the areas varied from 0,02 to 200 mR/h. The frequency of reciprocal translocations in mouse spermatocytes was relatively low and increased linearly with increasing of the dose rate. The levels of recessive lethal mutations in mouse populations did not depend on the radiation dose rate in the areas and decreased with a time.

[Modification of the genetic effect of radiation in mice exposed in the region of the Chernobyl Atomic Electric Power Station]. / Modifikatsiia geneticheskogo éffekta radiatsii u myshei, éksponirovannykh v raione Chernobyl'skoi AES.

A study was made of the protective effect of beta-carotine and ephasol against genetic damages in germ cells of male mice, exposed within the zone of Chernobyl NPP or ingested by 137Cs. The analysis of reproductive function, frequencies of dominant lethal mutations, abnormal sperm heads, reciprocal translocations and testis mass decrease show that both agents are more effective in protection against reproductive function damages than against genetic effects.

[The radioprotective action of efazol under different conditions of irradiation of the germ cells of male mice]. / Radiozashchitnoe deistvie éfazola pri raznykh usloviiakh oblucheniia polovykh samtsov myshei.

A study was made of the protective effect of ephasol against genetic damages induced in mice germ cells by single, fractionated and chronic gamma radiation. Study of male reproductive ability, frequency of induced dominant lethal mutations, abnormal sperm heads and reciprocal translocation show that the efficacy of ephasol was higher in condition of chronic exposure.

[Genetic effects of tritium-labeled amino acids in mice]. / Geneticheskie éffekty mechennykh tritiem aminokislot u myshi.

The frequency of dominant lethal mutations (DLM) in germ cells and the frequency of reciprocal translocations (RT) in spermatogonia of male mice exposed to H-labeled amino acids at the dose of 1.45-2.30 Gy was studied. The effect from H-glycine was equal to that from tritium oxide (THO). When D,L-lysine-3H and L-lysine-3H were injected into the body of mice the frequency of DLM exceeded that from the equal dose of THO by 2.5 and 7 times, respectively. As to RT, these indexes for H-amino acids have no statistically significant differences from the similar index for THO.

[Genetic effect of incorporated 137 Cs in male mice after single injection of the isotope]. / Geneticheskii éffect inkorporirovannogo 137 Cs u samtsov myshei pri odnokratnom vvedenii izotopa.

A comparative study of the incidence of genetic damages induced in mouse male germ cells by a single injection of 137Cs and external gamma-irradiation shows that the incidence of dominant lethal mutations in the postmeiotic cells is similar with both radiation types. The frequency of reciprocal translocations in stem cell spermatogonia was considerably lower with 137Cs than with external gamma-irradiation which might be attributed to the prolonged effect of the radionuclide.

[Genetic effect of incorporated 137 Cs on male mice after long-term administration of the isotope]. / Geneticheskii éffect inkorporirovannogo 137 Cs u samtsov myshei pri dlitelnom vvedenii izotopa.

A comparative study has been made of the incidence of genetic damages to male mouse germ cells induced by chronic action of incorporated 137Cs and external gamma-radiation. It has been shown that the genetic efficiency was nearly the same with both radiation types under conditions of equal, with respect to time and value, absorbed dose formation in gonads.

[Genetic disorders in laboratory mice, exposed in the region of the Chernobyl Atomic Power Plant four years after the accident]. / Geneticheskie narusheniia u laboratornykh myshei, éksponirovannykh v raione Chernobyl'skoi AES spustia 4 goda posle avarii.

Mice (CBA x C57BL)F1, of both sex and males C57BL were exposed within the 10 km zone of the Chernobyl Nuclear Power Station during 14, 22 and 34 days. Genetic damages of chronic radiation in the exposed adult mice, and in the course of embryogenesis, was studied. The gonadal absorbed radiation doses of the exposed mice varied from 0.5 to 1.5 Gy. The frequencies of dominant lethal mutations, abnormal sperm heads and reciprocal translocations linearly increase with increasing absorbed radiation doses. Among 49 males exposed at the embryonal stage one male heterozygote for reciprocal translocation was revealed. In other males of this group, reciprocal translocation yield was low. No uniform dependence of genetic effects from mice genotype was revealed.

[Genetic effects in mice exposed to the 10-km area around the Chernobyl Atomic Energy Station]. / Geneticheskie éffekty u myshei, éksponirovannykh v 10-kilometrovoi zone chernobyl'skoi AES.

Mice (CBAxC57BL) F of both sexes were exposed within the 10 km zone of Chernobyl nuclear power station. Genetic damage of phone chronic effect of increased radiation in exposed adult mice and in the course of embryogenesis was studied. The total absorbed radiation doses in testes varied from 1.85 to 0.42 Gy in embryos and from 3.4 to 2.7 Gy in adult males. Increase of dominant lethal mutations (DLM) and abnormal sperm heads (ASH) was only observed right after the end of exposure of adult males. The yield of reciprocal translocations (RT) in these males was relatively low. Among the males exposed at the stage of early embryogenesis, 4 heterozygotes for RT were revealed. In other males of this group the RT yield was low.

[Genetic disorders in laboratory mice exposed in the area of the Chernobyl Atomic Electric Power Station]. / Geneticheskie narusheniia u laboratornykh myshei, éksponirovannykh v raione Chernobyl'skoi AES.

Laboratory male mice (CBA X C57Bl)F1 were exposed in three sectors with different contamination degree of radionuclides within 30 km-zone of the Chernobyl Atomic Power Plant. The total absorbed radiation doses in testes were 0.1; 3 and 25 Gy, respectively. Great depression of spermatogenesis was observed in exposed mice up to complete sterility in males from the most contaminated sector. The mutagenic effect of radiation was relatively low and did not increase with growth of the contamination degree.

[Reciprocal translocations in mice found in the vicinity of the Chernobyl nuclear power station]. / Retsiproknye translokatsii u myshei, nadkhodivshikhsia v raione Chernobyl'skoi AES.

A study was made of the incidence of genetic damage to germ cells of male mice taken from or exposed within the thirty-kilometer zone of Chernobyl, the contaminated no-man's-land around the reactor that failed. At all contamination levels mouse spermatocytes exhibited reciprocal translocations, a relatively low frequency of which increased with increasing dose rate. Heterozygotes, with respect to reciprocal translocations (5%), were found among males exposed to enhanced radiation background as early embryos.