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Changes in the weight of reproductive system organs, quantitative and qualitative indicators of the epididymal spermatozoa of rats on the Ist and 30th days after the end of an electromagnetic exposition from the mobile phone (1745 MHz, the 8 hour/day, power density 0.2-20 μW/cm²) of various duration (from 1 to 90 days) have been researched. A significant increase in the absolute and relative weight of the epididymis and seminal vesicles and the number of epididymal spermatozoa was revealed on the 1st day after electromagnetic expo- sure during 7 days. The increase in the exposure duration up to 14 days is accompanied by a fall of the above indicators, and after a longer exposure (30, 60 days) there is an increase of the absolute weight of the testes; in all other cases, significant deviations in terms of the weight of reproductive organs are not observed. Expo- sition of various duration at 1745 MHz, except for 7-day radiation exposure, had no significant effect on the amount of epididymal spermatozoa and DNA fragmentation in them; however, viability of mature male germ cells in irradiated animals decreases independently of the duration of exposure. The revealed disturbances of the researched indicators are mainly normalized in the remote period (on the 30th day) after electromagnetic radiation.

We studied the state of the reproductive system of male rats after irradiation at a dose of 2.0 Gy, immobilization stress (6 hours/day for 7 days) and their combined effects. On the 30th day after the combined treatment (37 days after irradiation) a decrease in the testicular weight by almost 50% compared with the control and lesions connected with the process of spermatogenesis are observed. In the remote period--on the 60th day (67th after irradiation) the effect of irradiation and irradiation in combination with immobilization stress leads to a sharp drop in the number of epididymal sperm (up to 18% of the control), and a reduction of their viability. The reaction ofthe reproductive system to the immobilization stress is expressed in a certain increase in the mass of the testes and epididymis, moderate imbalances in the composition of spermatogenic cells in the testis tissue, and in the long term--in the increased number of epididymal sperm and the decrease in their viability. Changes of testosterone in the blood serum, especially significant for the combined effect, reflect impairments of the regulation of the reproductive system of males under these conditions. With regard to individual indicators of the reproductive system of male rats in some cases, the- combined effects of radiation and stress had a synergistic, or, on the contrary, antagonistic character.

The consequences of prolonged exposure to electromagnetic radiation from cellular phone (897 MHz, daily 8 h/day) in male rats of the 1st generation obtained from irradiated parents and subjected to prolonged exposure to electromagnetic radiation of the range of mobile communications during ontogeny and postnatal development were studied. It has been found that irradiation causes a decrease in the number of births of animals, changing the sex ratio towards the increase in the number of males. It had a significant impact on the reproductive system of males, accelerating their sexual development, revealed at the age of two months. Radiation from cell phones led to significant disproportions in the cell number at different stages of spermatogenesis. It increased the number of mature spermatozoa which decreased viability.

The study covered state of spermatogenic epithelium and dominant lethal mutations output in mice of BALB/c and CBA lines, subjected to total gamma-irradiation and in Wistar rats after intraperitoneal injection of potassium bichromate (K2Cr2,O7) in small and sublethal doses. The BALB/c line mice under low irradiation dose (0.25 Gy) demonstrated stimulation effect on spermatogenic epithelium, but in the CBA line mice no such effect was seen. Both mice lines under irradiation of 0.25 Gy and 1.0 Gy demonstrated increase in pathologic sperm counts and in percentage ofpreimplantation embryonal death. In rats, injection of potassium bichromate in doses of 0.028 mg/kg and 2.8 mg/kg increased number of micronuclear spermatids, larger pathologic sperm counts and percentage of postimplantation deaths. Thus, lower general embryonal deaths under radiation exposure is due to preimplantation embryonal deaths, under exposure to 6-valent chromium--is due to postimplantation losses.

The results of the genetic, cytogenetic and molecular analysis of the recessive mutations at the small, lying close to the centromere, cinnabar (cn) gene of Drosophila melanogaster induced by γ-rays of 60Co (doses 5-60 Gy) or 0.85 MeV fission neutrons (doses 2.5-20 Gy) in the mature sperm of the wild-type males from the laboratory line D32 are presented. The whole spectrum of the cn mutations induced by different quality radiation is found to be the same and consists of the two main-distinct classes such as gene/point and gene/chromosome mutations either of which includes the array of the subclasses (gene/point simple or complex mutations and chromosome rearrangements detected as F1 cn mutants with dominant sterility of multilocus deletions involving the cn gene wholly). The induction rate of both mutation classes is found to be increased linearly with dose of low- and high-LET radiation and the RGE values of neutrons are 1.0 and 4.0 for the gene/point and gene/chromosome mutations respectively. According to the data of the molecular analysis, 28 out of 59 (47.5%) γ-ray- and neutron-induced gene/point cn mutations studied are found to have the intragenic DNA alterations detected by PCR technique as a loss of the single or two adjacent fragments-amplicons non-randomly located at the 5'- or 3'- end of the gene map. Essentially, 10 out of 48 (20.8%) γ-ray-and 3 out of 11 (27.3%) neutron-induced gene/point mutations are found to show the same molecular "phenotype" (the loss of the two adjacent fragments at the 3'- end of the gene map) as that in the cn1 allele-marker from the maternal tester-line KL with the females of which the irradiated males were crossed. Among the putative recombination-based genetic processes underlying the exchange between the cn1 and damaged cn(+32) alleles, the gene conversion in the "gonomeric" nucleus of the zygote seems to be the most likely such processing. The established features of the cn gene radiomutability are compared with those earlier described for the other small gene black+ located in the middle of the 2L chromosome.

The article represents results of studies concerning influence of ionizing radiation on experimental animals under absolutely lethal doses of 8 Gy. In single total irradiation the rats demonstrate changes in lipoperoxic cascade products and suppressed activity of anioxidant defence enzymes in generative cells--that causes metabolic disorders.

The results of the genetic, cytogenetic and molecular analysis of the nature of heritable recessive mutations at the small black (b) gene of Drosophila melanogaster induced by different doses (5-10 Gy) of 60Co gamma-rays and 0.85 MeV fission neutrons in the mature sperms of the wild-type males from the laboratory line D32 are presented. The whole spectrum of the b mutations induced by radiation of different quality is found to be the same and consists of the two main classes such as gene/point and gene/chromosome mutations, the latter of which include the whole-genomic, infra- or inter-chromosomal rearrangements involving the b gene. The induction rate of both mutation classes is found to be increased linearly with a dose of low- and high-LET radiation and the effectiveness of neutrons is 2.7 and 4.6 as large as that of gamma-rays under the gene/point and gene/chromosome mutation induction, respectively. Essentially, the molecular alterations underlying 65 gamma-ray- and neutron-induced gene/point b mutations are found not to be detected by the PCR technique. These and other established features of the b gene radiomutability are drastically different from those of another larger vestigial gene described earlier. The nature of these differences is discussed within the framework of the current notion of different biological organization of the two genes mentioned above and of the track structure theory as well.

The screening of PCR-detected DNA alterations in 9 spontaneous and 59 gamma-ray-, neutron - or neutron + gamma-ray-induced Drosophila vestigial (vg) gene/"point" mutations was carried out. The detected patterns of existence or absence of either of 16 overlapping fragments into which vg gene (15.1 kb, 8 exons, 7 introns) was divided enable us to subdivide all mutants into 4 classes: (i) PCR+ (40.7%) without the detected changes; (ii) "single-site" (33.9%) with the loss of a single fragment; (iii) partial detections (15.2%) as a loss of 2-9 adjacent fragments and (iv) "cluster" mutants (10.2%) having 2-3 independent changes of(ii) and/or (iii) classes. All spontaneous mutants except one were found to be classified as (ii) whereas radiation-induced mutants are represented by all 4 classes whose interrelation is determined by the dose and radiation quality. In particular, the efficacy of neutrons was found to be nine times as large as that of gamma-rays under the "cluster" mutant induction. Essentially, the distribution of DNA changes along the gene is uneven. CSGE-assay of PCR+-exon 3 revealed DNA heteroduplexes in 5 out of 17 PCR+-mutants studied, 2 of which had small deletions (5 and 11 b) and 3 others made transitions (A --> G) as shown by the sequencing. Therefore, gamma-rays and neutrons seem to be significant environmental agents increasing the SNP risk for the population through their action on the germ cells. The results obtained are also discussed within the framework of the track structure theory and the notion of quite different chromatin organization in somatic and germ cells.

The level of damage DNA in neyroblastes of larvae and frequency of recessive sex-linked lethal mutations of males from chronically irradiated populations Drosophila melanogaster, differing on mobile P-elements patterns, was estimated. Received results testify, that exposition in conditions a chronic gamma-radiation (absorbed radiation dose at one generation is compounds 10 mGy) result to increase of significance of parameters and change of sensitivity of cells to following of an acute irradiation in a dose of 3 Gy.

The influence of constant magnetic field, power 7 T, and ultrasound, frequency 2, 4 and 8 MHz, on gametes, fertization, embryos and larvae of the sea urchin was studied. It was shown that magnetic field breaks the process of the gamete fusion but does not influence gametes, embryos, and larvae. Ultrasound impairs the motility of spermatozoa and larvae, prevents the fertilization, and breaks the embryonic development. It is assumed that the effect of the magnetic field is connected with the response of the cortical cytoskeleton, which consists of bundles of actin microfilaments. The rearrangement of the cortical cytoskeleton occurs during the first 20 minutes after the contact of sperm with the egg. Also there is effect of magnetic fields on calcium ions, which are liberated during the first seconds after gamete contact. The effect of the ultrasound is explained by a small increase in water temperature and cavitation process, which break celluar structures.

This review describes the results of some publications on monitoring radiation-induced mutation in the human germline. Recent data have shown that minisatellite loci provide a useful and sensitive experimental approach for monitoring radiation-induced mutation in humans. The progress made in validating this approach and the results of recent publications on the analysis of minisatellite mutation rates in the irradiated families are presented.

The exposure to low-intensity extremely high frequency electromagnetic radiation during spermatogenesis was accompanied by pathological changes, which resulted in degeneration and polymorphism of spermatozoa. The number of newborn rats increased in the progeny of irradiated animals.

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.

Diploid gynogenetic progenies were obtained in the stellate sturgeon Acipenser stellatus, Russian sturgeon A. gueldenstaedtii, and sterlet A. ruthenus by means of insemination of the eggs with UV-irradiated spermatozoa and suppression of the second meiotic division by heat shock. The gynogenetic nature of experimental fish was confirmed by RAPD-PCR analysis of DNA. Effective photoreactivation of UV-induced lesions of spermatozoa was shown in the case of illumination of the fertilized eggs with visible light. This phenomenon should be taken into account when determining the doses of irradiation that allow inactivation of the male chromosomes and incubating gynogenetic embryos. Gynogenetic stellate and Russian sturgeons are viable and can be reared in order to study the mechanism of sex determination in sturgeons.

It was studied the morphofunctional state of rat male reproductive system after chronically exposure to low intensive gamma-irradiation in early ontogenesis. After radiation with a total dose of 1.0 Gy it was revealed the decrease of the testes and epididymis weight, dysbalance in the ratio of different spermatogenic cells, changes in nucleic acid content and discoordination of bioenergetic metabolism in testes. Disturbance in rat male reproductive system retained in remote period (180 days after irradiation).

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 problem of hereditary effects of mammal exposure to ionizing radiation has a 95-year history but to date, no simple final solution has been available. Many papers on this problem specify the dependence of the hereditary effects on dose rate, regime, physical nature of radiation exposure, type, line and age of mammals that were studied. Over many years it was studied mainly as an aspect of hereditary radiation effects in progeny of one irradiated and the second non-irradiated parents. Recently due to the large-scale expansion of ionizing irradiation, it has turned out urgent to study hereditary radiation effects in progeny of both irradiated parents. However, the original studies on this problem are not numerous, and in the summarized articles, the problem practically had no specified presentation.

Actions of environmental impacts on mud loach spermatozoa were studied using various model systems: a) temperature stress, b) X-ray irradiation in vivo only of the animal head (a condition to trigger stress reaction), c) X-ray irradiation in vivo only of the animal body (a condition to exclude a direct activation of principal stress-realizing organism systems), d) gamma-irradiation in vitro of the cell suspension. It has been demonstrated that the temperature stress or X-ray irradiation of the mud loach head induced three lines of effects: 1) significant decrease in DNA superhelical density, 2) activity redistribution (functional activation) of DNase II between chromatin subfractions (with the increase of its association to chromatin), and 3) intracellular acidification up to pH value to satisfy the DNase II initiation. The obtained facts allow to suggest that, first, DNase II participates in the presented temperature- and radio-induced supercoiled DNA relaxation in spermatozoa, and, second, DNase II is involved in physiological (season elimination of spermatozoa that remained within male gonads after fertilization) or environmentally-induced DNA degradation.

D. Lea classic theory for chromosomal rearrangements formation was modified to account for local interaction of broken chromosome ends. This assumption drastically improve coincidence of the theory and experiment in the case of complex rearrangements.

The maternal effect of the mutation mus104D1 (defect of postreplication repair) on the yield of translocations involving heterochromatin breaks induced by irradiation of mature spermatozoa has been investigated. The mutation has been shown to bring about a threefold increase in the frequency of translocations. No significant maternal effect of this mutation on the frequency of mitotic exchanges induced by irradiation of mature hyperploid spermatozoa has been observed. This is in agreement with published evidence on properties of the mei41 mutation (allete mus104D1). However, our results are more accurate as both processes--formation of translocations and mitotic exchanges--were studied in the same tissue and at the same stage of development.

In studies on 120 mature males of Wistar rats and 252 female rats of the same line, 20-day-old fetuses and 974 young rats of the first generation, anomalies of antenatal and postnatal development were found after exposure of spermatids and spermatozoa to gamma-radiation in doses 0.25-1.0 Gy. After exposure of male rats to radiation in dose 0.25 Gy, reliable delay of pelvic bone ossification was observed as compared to the control.

Cytogenetic analysis of polytene chromosomes of Drosophila melanogaster locus-specific mutants induced by consecutive neutron-photon irradiation has shown that their genome contains multiple intra- and inter-chromosome exchanges, including triradials, evidencing the synergistic action of such combined exposure. The appearance of the triradials may be only possible on the base of an interaction between a double and a single DNA strand breaks. The important significance of such interaction as the general mechanism for production of chromosome aberrations in irradiated cells of higher eucaryotes had been postulated by N. V. Luchnik as early as 10 years ago, but only nowadays it has been confirmed experimentally.

Published data on the pattern and genetic control of early cleavage divisions in Drosophila melanogaster are summarized. Data on chromosome elimination induced by the mutation paternal loss (pal), elimination of ring and rod chromosomes, and mitotic exchanges in the hyperploid pronucleus in Drosophila suggest a specific structural role of heterochromatic chromosomal regions during early cleavage. Mutations disturbing early cleavage divisions include mutations with effects assigned to different stages of this process. This allows us to suggest the existence of isofunctional proteins involved in mitosis and alternating during early cleavage. In addition, cleavage divisions apparently include a special mechanism preserving primordia of germ tissue from unbalanced nuclei.

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.

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.

Distinct genetic radiosensitivity of germinal cells of males irradiated during different stages of spermatogenesis with doses of 0.25-5.0 Gy leads to reduction in vital newborn rats number in the first generation progeny and to elevated postnatal mortality rate. These postnatal ontogeny disorders depend on the irradiation dose and spermatogenesis stage for a moment irradiation.

The data on antenatal and postnatal periods of ontogenesis of the posterity of the first generation of Wistar rats exposed by doses of 2-4 Gy at various terms before conception showed that the realization of radiation effects depended on the stage of gametogenesis of sex cells of both parents at radiation exposure. Stimulating radiation effect (hyperovulation) is accompanied by the higher rate of antenatal and early postnatal death of the posterity. In the rest cases it died mainly at embryogenesis. The most unfavourable factor for ontogenesis of the posterity appeared to be a participation in the fertilization of sex cells exposed at postmeiotic stages of gametogenesis, with the degree of manifestation of radiation effects depending on radiation dose.

Acute gamma-irradiation with a dose of 4 Gy of germinal cells of both parents in postmeiotic stages of gametogenesis results in increase of ineffective copulation rate. Antenatal and postnatal ontogenesis of first generation progeny shows worse consequences as compared with only one parent germinal cell irradiation.

The purpose of the investigation is the study and comparative analysis of radiation effects observed in antenatal and early postnatal ontogenesis of first generation progeny when one or both parents have been irradiated in doses 2, 3, 4 Gy. It was shown that the effects for the posterity of both exposed parents were attributed mainly to a female if mature oocytes were exposed to radiation, or to a male if maturing oocytes were exposed. If both parents have been irradiated at the spermatid, spermatozoid or mature oocyte stages and got 4 Gy aggravated effects in progeny are observed. It is may be related to synergistic mechanism of realization of this phenomenon.

Single whole-body exposure of adult male rats Wistar in different stages of spermatogenesis to gamma-rays (doses from 0.25 to 5.00 Gy) resulted in violations of antenatal development of the first generation offsprings. The pronouncement of these violations depends on the spermatogenesis stage in the moment of irradiation and exposure dose.

The frequency of radiation-induced chromosome losses is not connected with heterochromatic content but depends on the total chromosomal DNA content. This dependence is of the selective nature and appears as a result of the effect of dominant lethality of non-repaired euchromatic breaks. Simultaneous losses of the two chromosomes in one nucleus are not independent, because of the interaction of the heterochromatic breaks underlying these losses. The conclusion is made that the chromosome losses are involved in the exchange events accompanied by the centromere deletion.

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.

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.

The method of determination of angiotensin-converting enzyme activity in human spermatozoa and sperm plasma was developed. The amount of total and active-mobile spermatozoa was shown to be less in Chernobyl victims than in healthy donors. Moreover, the specific activity of angiotensin-converting enzyme in Chernobyl victims spermatozoa calculated per 10(6) cells was 12-fold greater than in spermatozoa of the donors. Similar phenomenon, although to a les extent, was observed in patients with chronic prostatitis. The enzyme activity in blood serum and sperm plasma was also demonstrated to be similar for all groups investigated and equal to that in healthy donors.

The paper is devoted to actual problems of the intercellular regulatory relations in the male gonad of mammals. Literature data on this problem are analyzed as well as the results of the personal findings. The problem of the influence of sex cells on the somatic surroundings are analyzed from different standpoints. Grounds of the necessary accounting of data of the paracrine interrelations in the gonad are given for a principally new approaches to studying the histophysiology of this organ.

Frequencies of incomplete translocations in subcentromeric heterochromatin induced by gamma-rays in mature sperm were estimated in the "two right acrocentrics and left compound" system of Drosophila chromosome 2. The value obtained at 3000R was (2.5-2.9) X 10(-3). Apart from incomplete translocations leading to formation of new metacentrics, acrocentrics were also formed. It is suggested that they appear via reunion of fragments after replication of paternal chromosomes. Incomplete translocation were shown to be formed as a result of loss of centric heterochromatin fragment of acrocentric and acentric arm of the compound, as opposed to formation, due to loss of acentric heterochromatin fragment of acrocentric and centric fragment of the compound. Analysis of the dose-effect curve for half-translocations show that the latter are two hit events.

A frequency of induction of translocations taking place in mature sperm of Drosophila between heterochromatic portions of the 2L compound and 2R acrocentric was estimated to be 9.62 X 10(-3). This value is being compared with the previously estimated frequency of incomplete translocations in this system which is (2.5-2.9) X 10(-3). The ratio of frequencies of complete and incomplete translocations obtained was intermediate between the Panshin data, on the one hand, and those of Muller and Hershkowitz, on the other. The reasons for these discrepancies are under discussion. Based on the value obtained for this ratio, the probability of reunion of chromosome break (q) is calculated to be 0.79.

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.

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.

A collection of rearrangements in the left and right arms of Drosophila autosome-2 was established with use of the "non-disjunction test". Rearrangements were induced by gamma-ray irradiation of mature sperm. The observed frequencies of rearrangement configurations for the 4-breaks rearrangements demonstrated that only spatially close breaks can reunite. Rearrangements configurations observed for the 3-breaks rearrangements support rather the classic hypothesis of rearrangement formation than the exchange hypothesis.

Studies have been carried out on carp gynogenetic offspring by four autosome genes: Tf (transferrin), Est(s) (muscle esterases, slow), Est(f) (muscle esterases, fast), My (myogenes). Homozygosity and phenotypical homogeneity by all the loci studied are established for carps of the second generation of the induced gynogenesis. In the first generation obtained from heterozygous females, the correlation of homozygous offspring of two classes corresponding to the theoretically expected one (1:1). Heterozygous offspring makes (%): 5.0 (Tf), 9.1 (Est (s)), 28.4 (Est (f)). Three loci are mapped in relation to the centromere by heterozygote frequency. Genetic inactivation of the radiated sperm has been confirmed using biochemical markers. Due to the codominant nature of inheritance and high polymorphism, protein loci are considered to be convenuent genetic markers.

It was shown that low-level beta-radiation of tritium is much more effective than gamma-radiation of 137Cs with respect to reduction of the mouse testis weight. The RBE coefficient increases from 1.8 at a dose of 1 Gy to 2.2-2.3 at 0.1 Gy. On the basis of the data obtained by the authors and those reported in the literature a quality factor is proposed for tritium: QF = 2. Using THO and Na36Cl labels a mean water content of the testis cells, necessary for the estimation of a tritium-radiation dose absorbed, has been determined: gamma ct = 0.70 +/- 0.02 ml/g.

The frequency of dominant lethal mutations (DLM) in differentiating spermatogenic cells and of reciprocal translocations (RT) in stem spermatogonia, as well as the loss of testis mass were determined after the administration of 3.3 MBq/D-glucose-6(3)H to mice. The absorbed dose in germ cells amounted to 0.95 +/- 0.06 Gy with 17% of the dose being attributed to radiation from bound tritium. The levels of the genetic effects of DLM and RT and the dependence of the DLM frequency upon the stage of the irradiated cell were nearly the same as those observed in the experiment with tritium oxide. The loss of testis mass to 54% of the control, 30 days after exposure, resembled that produced by THO. The value of the reaction determined by all three tests was in accordance with the value of the absorbed dose with regard to the known doubled effectiveness of low-energy beta-radiation and did not need the hypothesis of the heterogeneity of the dose distribution and the influence of tritium transmutation.

Mass lost of diploid gynogenetic carp offspring were obtained with the use of fish-farm method of reproduction. The average yield of gynogenetic diploids in usual experiments was 0.1% (from fertilized eggs). The cooling of unfertilized spawn (at the stage of metaphase II) to 8--10 degrees C during 3.5--4.5 hours in 50% of cases permitted to increase by tens of times (in the most successful experiments up to 8%) the yield of gynogenetic diploids. The rate of survival of carps remained relatively low during the first two years of life, particularly during the first hibernation that is a critical period. No specific depression of growth in gynogenetic diploid carps was observed. A high yield of gynogenetic diploids (3.9% of fertilized eggs) and their relatively high rate of survival were observed in the second generation of artificially induced gynogenesis.