Различные стрессовые факторы приводят к повышению уровня активных форм кислорода (АФК) и усилению повреждения различных тканей растений. Избыточная продукция АФК при окислительном стрессе является частью многих стрессовых ситуаций, включая гипоксию и действие перекиси водорода. Целью данной работы было изучение влияния стрессовых факторов, таких как гипоксия и действие перекиси водорода, на образование и локализацию АФК у двух генотипов пшеницы Triticum aestivum и Triticum durum и защитного действия кверцетина от АФК.

The aim of the study was to study the state and reaction of cytoskeletal elements, microtubules and actin filaments, in root cells of Samsun tobacco plants and its transgenic line expressing the FeSOD1 gene from Arabidopsis thaliana with the pea rbcS leader sequence for the localization of the gene product in chloroplasts encoding Fe-dependent superoxide dismutase, constitutively inducing intracellular oxidative stress, by increasing the H2O2 pool for a long-term effect of moderate concentrations of NaCl and Na2SO4. The main hypothesis was to identify the positive protective effect of controlled constant oxidative stress on the stability of the most sensitive system that provides growth by division and growth by extension (the tubulin cytoskeleton) and effective intracellular transport and structural stability (the actin filament system). Localization of the microtubule cytoskeleton and actin filaments using antibodies to tubulin clone DM1α and actin clone 10-B3 by transmission electron microscopy and immunocytologically, detected by treatment with the second antibodies conjugated with Alexa‑488, made it possible to establish signs of reorganization and disassembly of the actin filament network under the action of NaCl and Na2SO4 as in control and in transgenic plants. At the same time, in transgenic plants, differences can be noted even without exposure, which indicates the effectiveness of this method for stimulating a protective response. These data suggest that the state of the system of the tubulin cytoskeleton and actin filaments may be an indicator of the resistance of FeSOD1 transgenic plants to salinity. A relationship has also been established between the reorganization of the cytoskeleton and vacuolization, especially with Na2SO4.

Odontocete echolocation has been actively studied in captivity, but there are few studies in the wild.Before 1980, dolphin echolocation was studied in captivity where the conditions are easier to make a controlled experiment and to interpret the results.But studies in the wild are important to observe how dolphins use echolocation under natural conditions.Among the few studies of killer whale echolocation in the wild, it has been shown that killer whales can detect a school of fish at a distance of about 100m (Au[1]).showed that two killer whale ecotypes -fisheating (resident) and mammal-eating (transient) -differed in certain characteristics of their echolocation trains.also studied some parameters of the echolocation trains of resident killer whales, but they did not separate them into different types of activity.The purpose of our study was to document, measure, and analyze the echolocation parameters of free-ranging resident killer whales, Orcinus orca, from Kamchatka, Far East Russia, during different types of activity.

A comparative analysis of tomato roots regenerated in vitro on media supplemented with different NaCl concentrations (0–250 mM) has been carried out. A morphogenetic study performed at the organ level has determined rhizogenesis-inhibiting NaCl concentrations, while the morphometric analysis of regenerated roots in juvenile seedlings has registered such characteristics as their number, length, and fresh/dry weight. A cytological study has revealed some tissue disorders, such as changes in the vacuolization of root cap cells and root cortex cells (RCC) under salinity conditions. At some NaCl concentrations, significant changes in the cells of these tissues have been observed in relation to such parameters as the root cap length (50–100 and 250 mM NaCl), the number of root cap layers (50, 75, 150–250 mМ NaCl), the area of central cylinder cells (CCCs, 75–150 and 250 mM NaCl), the RCC area (100–200 mM NaCl), and the nucleolus to nucleus ratio (25, 50, and 200 mM NaCl). Using cytophotometry, we have shown there to be an increase in the number of interphase cells of the root meristem in the G2 phase with a simultaneous decrease of this parameter in the G1 phase. Immunofluorescent labeling has revealed various disorganizations in the alpha-tubulin cytoskeleton of interphase root meristem cells. Using transmission electron microscopy, we have revealed structural changes in plastids of root cap cells, RCC, and CCC, as well as changes in the organization of a nuclear compartment in RCC occurred in the presence of 150 mM NaCl. The studied characteristics can be used for a comparative evaluation of tomato genotypes under salinity at different levels of their organization. The proposed approach can be also used for crops that have no difficulties with induced rhizogenesis in vitro.

The process of programmed cell death is essential for plant ontogenesis. Seed development reveals the key role of programmed cell death in cell elimination and formation of new structures. Morphological data and biochemical regulators of programmed cell death during formation of the embryo sac and seed are discussed in the review.

The study objective is to analyze the content of spermatozoa with single and double-stranded DNA breaks in different age groups. Materials and methods . The level of DNA fragmentation was studied in 300 ejaculate samples obtained from 266 sub- or infertile men. The group 1 included 150 samples obtained from 131 patients under the age of 45 (21–44 years), the group 2 included 150 samples obtained from 135 patients above the age of 45 (45–68 years). Mean ages were 34.8 ± 3.9 and 48.6 ± 3.1 years, respectively. The number of sperm with fragmented DNA was evaluated using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method on ejaculate smears. The number of spermatozoa with >15 % of fragmented DNA was considered elevated. Standard semen analysis was performed in 117 and 97 men from the groups 1 and 2, respectively. Results . The number of sperm with fragmented DNA varied in ejaculated samples from 1.5 to 64.5 %. Mean number of sperm with DNA breaks in the group 1 (12.0 ± 6.0 %) was significantly lower than in the group 2 (16.1 ± 8.3 %, p <0.05). Mean sperm count in the ejaculate of the group 1 (267.0 ± 198.7 million) was significantly higher than in the group 2 (201.0 ± 162.9 million, p = 0.02). Conclusion . We revealed that in men over the age of 45 years, the percentage of spermatozoa with DNA fragmentation is higher than in men under 45 years of age, it may indirectly indicate an increased level of reactive oxygen species in the seminal plasma in older patients.

The study objective is to analyze the content of spermatozoa with single and double-stranded DNA breaks in different age groups.Materials and methods. The level of DNA fragmentation was studied in 300 ejaculate samples obtained from 266 sub- or infertile men. The group 1 included 150 samples obtained from 131 patients under the age of 45 (21–44 years), the group 2 included 150 samples obtained from 135 patients above the age of 45 (45–68 years). Mean ages were 34.8 ± 3.9 and 48.6 ± 3.1 years, respectively. The number of sperm with fragmented DNA was evaluated using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method on ejaculate smears. The number of spermatozoa with >15 % of fragmented DNA was considered elevated. Standard semen analysis was performed in 117 and 97 men from the groups 1 and 2, respectively.Results. The number of sperm with fragmented DNA varied in ejaculated samples from 1.5 to 64.5 %. Mean number of sperm with DNA breaks in the group 1 (12.0 ± 6.0 %) was significantly lower than in the group 2 (16.1 ± 8.3 %, p <0.05). Mean sperm count in the ejaculate of the group 1 (267.0 ± 198.7 million) was significantly higher than in the group 2 (201.0 ± 162.9 million, p = 0.02).Conclusion. We revealed that in men over the age of 45 years, the percentage of spermatozoa with DNA fragmentation is higher than in men under 45 years of age, it may indirectly indicate an increased level of reactive oxygen species in the seminal plasma in older patients.

A detailed study into the structural features of the multilevel antipodal complex of wheat Triticum aestivum L. embryo sac was performed at different stages of the complex’s differentiation after double fertilization. The heterogeneity of nuclei ploidy in individual antipodal complexes caused by the asynchrony of the endoreduplication rounds of the nuclear DNA was revealed. The nuclei ploidy of basal, middle, and apical layers of the complexes was measured at the early, middle, and late stages of differentiation. At the early stage of differentiation, the nuclei ploidy of the antipodal complex’s basal layer adjacent to the chalasal region of the nucellus of the embryo sac reaches 13 C, the nuclei of the apical layer cells that contact the endosperm syncytium reaches 63 C, and the nuclei of the middle layer located between the basal and apical layers reach 30 C. At the middle stage of differentiation, the nuclei ploidy in the basal layer increases to 17 C. The nuclei ploidy of the apical layer cells increases to 95 C, and nuclei ploidy of the middle layer increases to 45 C. At the stage of late differentiation, the nuclei ploidy in the basal layer increases to 24 C; the apical layer ploidy increases to 215 C; the middle layer ploidy increases to 63 C. Changes in the shape and structure of the nuclei during differentiation were revealed. They manifest themselves in heterogeneity in shape, size and structure of chromatin; the formation of individual polytene chromosomes; nuclear membrane invaginations; and the variation in the number of nucleoli. Data on the distribution and structure of cytoplasmic organelles of the antipodal cells, endoplasmic reticulum, dictyosomes, mitochondria, and microtubules at different stages of differentiation of the antipodal complexes are fundamentally new. The increased number of cytoplasmic organelles was revealed. During the differentiation, prolong cisterns of the granular reticulum are replaced by concentric rings, mitochondria and plastids of extended and cupped shape appear, and the microtubule network is rebuilt. The features of the antipodal complex’s cell structure may reflect changes in the functions of the antipodal complex during the differentiation. At the early stage, all cells of the complex perform an osmoregulatory function, and cells of different layers of the complex specialize at the middle stage of differentiation. The ploidy level of cell nuclei with polytene chromosomes reflects their functional significance in the formation of endosperm at the nuclear stage of development, and, subsequently, of normal full-fledged grain.

Introduction. In the last decade, an understanding of the two-fold nature of genetic apparatus damage in spermatozoa has emerged: abnormal chromatin condensation (“immature” chromatin, ICH) related to defective protaminization and leading to altered epigenetic regulation of the early embryogenesis, and disruption of DNA integrity, i. e. DNA fragmentation (DFS).Objective. Study of the correlation between abnormal chromatin condensation in spermatozoa and DFS.Materials and methods. The study included spermatozoa of 54 fertile males (1st group, control), 46 patients with primary infertility (2nd group), and 111 patients whose wives had a history of pregnancy abnormalities or failures of the assisted reproductive technology (ART), i. e. arrested embryonic development (3rd group). Presence of ICH was identified by quantitative electron microscopy, presence of DFS by TUNEL. Study of ICH and DFS in the same spermatozoon was conducted using correlation microscopy (TUNEL with subsequent ultrastructural analysis of the labeled cells).Results. The number of ICH spermatozoa significantly differed in the 3rd group from the control group (29.26 ± 13.49 vs. 22.43 ± 9.54; p = 0.006). The number of ICH spermatozoa in the 2nd group was higher than in the control group, but the difference wasn’t statistically significant (p = 0.061). A significant difference in the number of spermatozoa with residual cytoplasm on the head was observed between the fertile group and 2nd and 3rd groups (p = 0.0001 and p = 0.0006, respectively) and on the neck (p = 0.0002 and p = 0.0003, respectively). Number of DFS spermatozoa in the second group significantly differed from the control (21.40 ± 11.88 vs. 13.70 ± 7.00, p = 0.03), but this difference wasn’t observed for the 3rd group. A very weak correlation between the number of DFS and ICH spermatozoa was observed in all three groups (r = 0.18, r = 0.33, and r = 0.01, respectively). Forty-six (46) spermatozoa were studied using correlation microscopy, among them 23 were DFS and 23 were ICH. In 11 of 23 HDS spermatozoa DFS was observed. In spermatozoa with condensed chromatin, DFS was identified in 6 spermatozoa.Conclusion. DFS and abnormal chromatin condensation are highly independent parameters, which should be considered during identification of the cause of infertility. ICH is more frequent in spermatozoa of patients whose wives have a history of embryogenesis abnormalities. DNS is more frequent in primary infertility.

We examined the organization of microtubule system of interphase cells in roots of Medicago sativa L. during acclimation to salt and osmotic stress at different concentrations of NaCl, Na2SO4, and mannitol. We identified morphological changes of tubulin cytoskeleton in different root tissues during the acclimation to salt and osmotic stress: (1) decreased density of the cortical microtubule network, (2) random orientation of cortical microtubule bundles, (4) thickening of the bundles, (3) nonuniform density of the bundles, (4) fragmentation of the bundles, and (5) formation of microtubule converging centers. Network thinning and thickening of the bundles were observed both under osmotic and salt stress. Random orientation of cortical microtubules was visualized under osmotic stress but not during salt stress. Fragmentation of microtubule bundles took place under salt stress with a high concentration of mannitol. Formation of microtubule converging centers was common under prolonged action of sodium sulfate, less evident under sodium chloride, and not found after mannitol treatment. Our data show that, in alfalfa root cells, cortical microtubules rearrange not only in response to different ions, but also to osmotic pressure. Thus, the signaling pathways and molecular mechanisms inducing reorganization of the microtubule system may be triggered by sodium cations, as well as by sulfate and chloride anions at concentrations that do not cause irreversible cell damage.