Vol 44, No 5 (2017)
- Year: 2017
- Articles: 13
- URL: https://journals.rcsi.science/1062-3590/issue/view/11395
Cell Biology
Effects of hypoxanthine at low concentrations on in vitro maturation and fertilization of bovine oocytes
Abstract
The effects of hypoxanthine (HX) at low concentrations on the ability of bovine oocyte to mature to metaphase 2 (M2) and to fertilize in vitro have been studied. It is proved that exogenous HX even at a low concentration, which was introduced into the HX-free and protein-free alpha-MEM medium supplemented with 1 μg/mL follicle-stimulating hormone, can significantly decrease the proportions of both the oocytes the matured to stage M2 and the penetrated and normally fertilized oocytes. It is indicated that the data may be used in order to develop commercial media for in vitro maturation of oocytes of mammalia, including humans.
Biochemistry
Regulatory and physicochemical properties of isoforms of succinate dehydrogenase from sulfur-reducing bacteria Sphaerotilus natans strains D-506 and D-380
Abstract
It was shown that in the conditions of organotrophic growth of colorless sulfur-reducing bacteria Sphaerotilus natans there was only one form of succinate dehydrogenase (SDH) and there were two in the mixotrophic type of nutrition. Three isoforms of SDH from S. natans with different nutrition types were obtained in an electrophoretic homogeneous substance. A quaternary structure of all isoforms was represented by heterotetramer. It was noted that the catalytic and regulatory characteristics of the isoforms involved in the tricarboxylic acid cycle had similar values. The thermodynamic characteristics of the isoforms of SDH and their thermal stability were determined.
Genetics
Microsatellite loci variability in the ural population of Silene latifolia (caryophyllaceae)
Abstract
Microsatellite primers designed for American and European populations of the white campion and Nottingham catchfly were tested on white campion samples from six Ural populations. It was noted that the loci studied are represented by 2–43 alleles and the average observed heterozygosity varied from 11 to 100%. It was established that 2 of the 14 loci studied can be considered as markers for radiobiological studies.
Microbiology
Molecular genetic and chemotaxonomic identification of the bacterium of the genus Ochrobactrum possessing oil-oxidizing and nitrogen-fixing activity
Abstract
It was shown that analysis of cellular fatty acids using gas chromatography-mass-spectrometry and application of the gene encoding β-subunit of DNA gyrase (gyrB) as an alternative phylogenetic marker supplemented the taxonomic description of the biotechnologically valuable strain Ochrobactrum sp. IB DT-5.3/2 but were ineffective for species identification of the bacterium. However, based on the results of the matrixassisted laser desorption-ionization time of flight mass spectrometry of the protein fractions and our previous studies of the cultural–morphological and biochemical features, as well as sequencing of the 16S rRNA gene, we can conclude that the strain Ochrobactrum sp. IB DT-5.3/2 refers to the species O. intermedium.
Reversion of nonculturable forms of Listeria monocytogenes under the influence of exometabolites of Aranicola spp.
Abstract
It was established that the exometabolites of Aranicola spp., isolated from beef, promoted the reversion of nonculturable forms of Listeria monocytogenes, isolated from the same product, into the proliferative state, influencing the expression of their biological properties, which was expressed by a change in the morphology and enzymatic properties of the colony, and also by an increase the hemolytic activity and a decrease in adhesiveness. It was noted that all changes in the biological properties of L. monocytogenes were phenotypic. Passage in trypticase-soy broth with further seeding of Listeria on yeast agar after the third passage led to a gradual change in the biological properties, until their complete recovery after the fifth passage on the sixth day of the study.
Botany
The dynamics of the central russian meadow steppes and the problem of their preservation
Abstract
The structure and dynamics of vegetation of the zonal central Russian meadow steppes have been studied with the example of the Privolzhskaya Forest–Steppe State Nature Reserve. Under the influence of a completely protected mode, the vegetation of the studied meadow steppes on the watershed surfaces was subjected to varying degrees and mesophytization and sylvatization. It was noted that these processes occur more intensively in the meadow steppe landscapes of secondary moraine plains (Poperechenskaya steppe and Ostrovtsovskaya forest–steppe) than in the meadow steppes of erosion-denudation plains (Kuncherovskaya forest–steppe).
Zoology
Embryonic development of mushroom bodies in Pterostichus niger schall. (Coleoptera: Carabidae)
Abstract
This study demonstrates that the number of stem cells in mushroom bodies of the ground beetle Pterostichus niger increases already in the first half of embryogenesis and that this timing allows for an intensive increase of the number of neurons that compose the mushroom bodies during the second half of embryonic development. The degree of development of the mushroom bodies in new-born P. niger larvae was shown to be higher than that in new-born larvae of any other holometabolous insect investigated previously.
Concentration and size distribution of plant fiber in the digestive tract of muroid rodents
Abstract
The weight parameters that characterize the size and the degree of fullness of fermentation chambers (forestomach and cecum), namely, the weight of the walls and the content of these organs, and the concentration and size distribution of fibers in the chyme have been investigated in five muroid rodent species (Arvicola terrestris, Microtus oeconomus, Microtus arvalis sp., Clethrionomys glareolus, and Sylvaemus flavicollis). No distinct regularities were observed in the above-mentioned parameters of the forestomach. These parameters of the cecum were generally found to be in good agreement with the conventional concept of dietary specialization of the rodent species under investigation, but the results have provided a more precise assessment of the role of dietary fiber in the diet of free-living rodents under specific environmental conditions.
Animal and Human Physiology
The role of testosterone in the regulation of P-glycoprotein functioning
Abstract
The functional activity of P-glycoprotein (Pgp) was studied in Chinchilla rabbits after orchiectomy and administration of testosterone undecanoate after surgery. The functional activity of Pgp was determined by the pharmacokinetics of fexofenadine, its marker substrate. In addition, the localization of the transport protein was assessed in the liver, kidney, and jejunum by the immunohistochemistry. It was found that a decrease in the serum testosterone concentration after orchiectomy leads to an increase in Pgp activity on the 14th and 21st days after the surgery, which is accompanied by an increase in the staining intensity of Pgp-positive epithelium membranes of the proximal and distal renal tubules. It was found that the administration of testosterone at a dose of 6 mg/kg body weight in the period after the surgery neutralizes these changes.
Hydrogen peroxide stimulates exocytosis of von Willebrand factor in human umbilical vein endothelial cells
Abstract
The aim of our research was to study the influence of hydrogen peroxide on the exocytosis of von Willebrand factor (vWF) in human umbilical vein endothelial cells (HUVEC). We have found that H2O2 at a non-toxic concentration (100 μM) increases the amount of vWF secreted by HUVEC by 43 ± 14% over control (p < 0.03) and elevates total exposition of vWF on cell surface by 89 ± 5% (p < 0.01). Analysis of immunofluorescent images of HUVEC with CellProfiler program revealed that the average number of antigen positive structures on the single cell surface increases from 11.4 ± 0.16 in control up to 17.5 ± 0.21 after incubation with H2O2 (p < 0.01). vWF is exposed on the cell surface as dots with the average sizes around 1–3 μm. H2O2 causes an increase in the number of these dots and the appearence of the strings of vWF which are absent in control HUVEC. It is suggested that H2O2 may serve as a messenger which stimulates vWF exocytosis.
Ecology
Experimental investigation of natural populations of Daphnia galeata G.O. Sars from the Curonian Lagoon feeding on potentially toxigenic cyanobacteria
Abstract
The results of laboratory experiments on studying the characteristics of feeding of natural populations of Daphnia galeata from the freshwater Curonian Lagoon on cyanobacteria using the counting and radioisotope methods are discussed. The consumption and assimilation of the cyanobacterium Aphanizomenon flos-aquae by Daphnia have been revealed, as has the inhibition of feeding in Daphnia by species of the genus Microcystis. The results of PCR analysis of the total DNA of plankton from the Curonian Lagoon and enzyme-linked immunosorbent assay have proved the ability of Microcystis populations to produce microcystins, while no genes involved in the synthesis of cyanotoxins have been found in A. flos-aquae.
Use of a geometric morphometric method to determine the developmental stability of Betula pendula Roth
Abstract
A geometric morphometric method has been proposed to test the fluctuating asymmetry and the developmental stability of Betula pendula Roth populations. The main factors affecting the developmental stability were the industrial emission level, the relief altitude, and the interaction of both these factors. A strong correlation between the fluctuating asymmetry indices obtained by the normalizing difference method and geometric morphometric method has been revealed. The fluctuating asymmetry determined by the geometric morphometric method is sensitive to the presence of directional asymmetry, which makes it possible to use this method for precise bioindication mapping of the developmental stability.
Dynamics of the horizontal structure of the tree stand in a pristine herb–bilberry forest of the subzone of the middle tiaga in the Komi Republic
Abstract
According to observations from 1987 to 2010 on a constant sampling plot, using spatial statistics, we have shown dynamics of the horizontal structure of all-aged stands of a pristine spruce herb–bilberry forest. We note that the trees forming it provide a continual change of generations and, therefore, random community structure and its spatial stability. We determined that small-leaved arboreal plants, which represent part of the tree stand, tend to grouping at distances from 4 m. It was discovered that the mutual arrangement of trees of different sizes and species do not differ from a random occurrence.