Peculiarities of growth of the monocellular green algae culture after the influence of electromagnetic field in deuterated water-containing media

Exposing the inoculum of monocellular green algae Dunaliella tertiolecta and Tetraselmis viridis to 50 Hz electromagnetic field for several hours resulted in a reduced growth rate in both cultures. It was ascertained that heavy water inhibited growth of algae Dunaliella tertiolecta. The light water activated growth of the culture in the exponential phase only.     

Revealing of allelic polymorphism in the populations of parthenogenetic lizards <Emphasis Type="Italic">Darevskia dahli</Emphasis> (Lacertidae) using locus-specific PCR

Locus-specific PCR was used to study the genetic polymorphism in three populations of parthenogenetic lizard species Darevskia dahli. The analysis was carried at the two (GATA) _n -containing loci (Du215 and Du281) using the sample of 26 individuals. A total of eight Du215 and three Du281 allelic variants were detected. It was demonstrated that all the lizards examined were heterozygous at these loci. In 12 animals, unusual Du215 allelic variant was revealed, the origin of which was thought to be associated with different types of genomic rearrangements, or segmental duplication. The populations studied were substantially different relative to the levels of allelic polymorphism, which could be explained by different habitation conditions, leading to accumulation of mutations in noncoding genome regions.     

Low Efficiency of Short-Term Tests in the Assessment of the Potential Mutagenic Hazard of Chemical Compounds to Mammals

A new method of the efficiency assessment of testing mutagenicity chemical pollutants is proposed. The method is based on the selective information criterion and allows one to compare the prognostic significance of results obtained in both individual tests and test batteries. The efficiency of mutagen detection in mammals was estimated in Ames' test, the in vivo test for cytogenetic abnormalities in rodent bone-marrow cells, and the battery combining both these tests. The level of evidence for mutagenicity was determined for chemicals analyzed in these tests. Based on information obtained during the trials, a low efficiency of the analyzed tests and their battery was inferred.     

Detection of genetically unstable loci in parthenogenic families of lizards of theLacerta genus by DNA fingerprinting

Two parthenogenic families of unisexual species of Caucasian rock lizards of genusLacerta, L. armeniaca andL. unisexualis, were analyzed by DNA fingerprinting. Inheritance of M13 minisatellite and of (GACA) _n , (GATA) _n , and (TCC) _n microsatellite loci in the first generation of the lizards was studied. M13, (GACA) _n , and (TCC) _n loci in the families ofL. armeniaca were strictly inherited, as well as M13 and (GACA) _n loci in the families ofL. unisexualis: each DNA fragment in the fingerprint patterns of progeny could be detected in the maternal pattern. However, when a (TCC)₅₀ microsatellite probe was applied in the study ofL. unisexualis families, specific DNA fragments with altered mobility were revealed in the progeny patterns, and the frequency of such events was rather high. It might be hypothesized that some of the (TCC) _n loci inL. unisexualis genome are highly mutable. Hence, the family analysis allowed us to demonstrate experimentally the presence of genetically unstable loci in genomes of parthenogenic species of vertebrates. The nature and mechanism of the instability of these loci in parthenogenesis remain obscure.     

Efficiency of Batteries of Tests for Estimating Potential Mutagenicity of Chemicals

A new method for assessing the efficiency of batteries of arbitrary numbers of tests is proposed. The posterior probability of the mutagenicity of the substances studied has been estimated using discriminant analysis. The results of tests in each test system has been presented as the probability to obtain a positive result in the given test system. This has made it possible to decrease the sample size as the number of tests in the battery increased. As a result, prognostic power may be assessed even if the matrix of results is incomplete. This approach has been used to estimate the weights of evidence for mutagenic activities of 105 chemical compounds studied by means of a battery of four tests: Ames's test, the test for chromosome aberrations in vitro, the test for cytogenetic defects in vivo, and the test for dominant lethal mutations in rodents.     

Gender Differences in Spontaneous and Evoked Activities of the Human Brain

The purpose of this study was to analyze sex-related differences in spontaneous and evoked brain activity. The study included 11 women and 10 men aged between 18 and 27 years; the subjects were adapted to the conditions of electrophysiological experiment. Differences in spontaneous activity were estimated by EEG spectral characteristics in frequency ranges corresponding to θ, α, β₁, β₂, γ₁, and γ₂ rhythms at rest with the eyes open and closed. The differences in evoked activity were estimated by the parameters of evoked potentials (EP) recorded upon the presentation of different types of stimuli (images and words) and categories (“fruits” and “vessels”). Behavioral differences were estimated by the efficiency of stimuli recognition. No gender differences were observed in the efficiency of stimuli recognition (number of errors, time of reaction). In the EEG of male subjects at rest, fast frequencies (β and γ) were less marked than in the female subjects, which may indicate a higher level of activation of CNS structures in women. Regardless of stimuli type and category, the amplitude of EP components in men is lower than that in women, which may be caused by lower level of CNS activation. However, the difference in the latency of EP components depended on the type of stimuli used. During the recognition of visual images, the latency of earlier EP components (N1, P2) in men was longer mostly on back and/or right electrodes. The latencies of the later EP components (P3, N3) in male subjects were longer on the back electrodes and shorter on the front electrodes than those in female ones. During the recognition of words, the latency of P1, N1, P2 and N2 components in men were shorter on temporal and temporoparietal electrodes of the left hemisphere. This may indicate that visual image in men are perceived slower but comprehended faster than in women. On the other hand, verbal stimuli in men were perceived faster but comprehended slower than in women.     

Investigation of the culture growth of unicellular green algae by the method of noninvasive analysis

Additional results on the process taking place in the growing culture of Dunaliella tertiolecta and cell exometabolites are obtained. Comparison of the absorption spectrum of culture liquid in different times of cultivation showed their differences and connection with reaction ability. Degradation of the external layers of cells at different phases of growth and quantitative changes of their biochemical composition and spatial orientation are shown. Correlation of the results obtained using the method of noninvasive analysis and the data of the preceding study is demonstrated.