Metagenomic analysis of microbial communities of the sediments of the Kara Sea shelf and the Yenisei Bay

Microbial diversity in the sediments of the Kara Sea shelf and the southern Yenisei Bay, differing in pore water mineralization, was studied using massive parallel pyrosequencing according to the 454 (Roche) technology. Members of the same phyla (Cyanobacteria, Verrucomicrobia, Actinobacteria, Proteobacteria, and Bacteroidetes) predominated in bacterial communities of the sediments, while their ratio and taxonomic composition varied within the phyla and depended on pore water mineralization. Increasing salinity gradient was found to coincide with increased share of the γ-Proteobacteria and decreased abundance of α- and β-Proteobacteria, as well as of the phyla Verrucomicrobia, Chloroflexi, Chlorobi, and Acidobacteria. Archaeal diversity was lower, with Thaumarchaeota predominant in the sediments with high and low mineralization, while Crenarchaeota predominated in moderately mineralized sediments. Microbial communities of the Kara Sea shelf and Yenisei Bay sediments were found to contain the organisms capable of utilization of a broad spectrum of carbon sources, including gaseous and petroleum hydrocarbons.     

Diversity of cultivable bacteria isolated from the water column and bottom sediments of the Kara Sea shelf

In this work, the results of microbiological and molecular genetic investigation of the microorganisms inhabiting the Kara Sea and the adjacent Yenisei and Gydanskii Bays are presented. The microorganisms isolated from the samples collected in the studied area belonged to 4 phyla and 11 genera. Bacteria of two phyla, Firmicutes and Actinobacteria, prevailed; representatives of the Gammaproteobacteria and Bacteroidetes were isolated as well. According to their phenotypic properties, the obtained pure cultures were classified with the genera Streptomyces, Rhodococcus, Micrococcus, Bacillus, Pseudomonas, Acinetobacter, Flavobacterium, and Marinococcus. Analysis of the obtained nucleotide sequences of the 16S rRNA genes confirmed that the isolates belonged to the genus Bacillus. One strain was reidentified as Brevibacillus laterosporus, and two strains were identified Aeromonas piscicola and Plantibacter sp. The results of the study of the enzymatic activity of the obtained pure psychrotolerant cultures suggest that the microbial community is actively involved in the destruction processes occurring in the studied area.     

Possibility of decreasing the anticomplement activity of human immunoglobulin preparations via chemical modification

The physicochemical and immunological properties of the experimental batches of the preparations of placental immunoglobulin, obtained by some methods of chemical modification of the molecule of IgG, have been studied. The possibility of abolishing the anticomplement properties of the preparations treated with sulfitolytic agents manufactured in the USSR has been shown. The optimum conditions permitting the production of the preparation with faintly pronounced anticomplement properties and the full monomer structure of its molecule have been established.     

Karyotype stability of 2 continuous Chinese hamster cell lines--CHO-K1 and V-79

Karyotypes of two continuous Chinese hamster cell lines CHO-K1 and V-79 were studied by G-banding and silver staining. Modal chromosome numbers were 20 and 21, respectively. Both the lines were characterized with a high degree of karyotype stability and constant ratio of normal and marker chromosomes. Nulli- and monosomy were recorded for 9 chromosome pairs in CHO-K1, and 8 pairs in V-79 cell lines. Modal numbers of Ag-positive NOR were 4 in CHO-K1 and 5 in V-79. A definition of the origin of the majority of marker chromosomes in both the lines (11 and 10, respectively) made it possible to establish the exact chromosome content of each cell and to determine the generalized reconstructed karyotypes of cell lines. We established the retention of diploid chromosome set of all the autosomes, the true monosomy for one X-chromosome in both the lines, and the constant extracopying of a short arm of chromosome 3 in the V-79 cell line.     

A Specific IFIH1 Gain-of-Function Mutation Causes Singleton-Merten Syndrome

Singleton-Merten syndrome (SMS) is an infrequently described autosomal-dominant disorder characterized by early and extreme aortic and valvular calcification, dental anomalies (early-onset periodontitis and root resorption), osteopenia, and acro-osteolysis. To determine the molecular etiology of this disease, we performed whole-exome sequencing and targeted Sanger sequencing. We identified a common missense mutation, c.2465G>A (p.Arg822Gln), in interferon induced with helicase C domain 1 (IFIH1, encoding melanoma differentiation-associated protein 5 [MDA5]) in four SMS subjects from two families and a simplex case. IFIH1 has been linked to a number of autoimmune disorders, including Aicardi-Goutières syndrome. Immunohistochemistry demonstrated the localization of MDA5 in all affected target tissues. In vitro functional analysis revealed that the IFIH1 c.2465G>A mutation enhanced MDA5 function in interferon beta induction. Interferon signature genes were upregulated in SMS individuals’ blood and dental cells. Our data identify a gain-of-function IFIH1 mutation as causing SMS and leading to early arterial calcification and dental inflammation and resorption.     

Role of the methionine cycle in the temperature-sensitive responses of potato plants to potato virus Y

Plant–virus interactions are greatly influenced by environmental factors such as temperatures. In virus-infected plants, enhanced temperature is frequently associated with more severe symptoms and higher virus content. However, the mechanisms involved in such regulatory effects remain largely uncharacterized. To provide more insight into the mechanisms whereby temperature regulates plant–virus interactions, we analysed changes in the proteome of potato cv. Chicago plants infected with potato virus Y (PVY) at normal (22 °C) and elevated temperature (28 °C), which is known to significantly increase plant susceptibility to the virus. One of the most intriguing findings is that the main enzymes of the methionine cycle (MTC) were down-regulated at the higher but not at normal temperatures. With good agreement, we found that higher temperature conditions triggered consistent and concerted changes in the level of MTC metabolites, suggesting that the enhanced susceptibility of potato plants to PVY at 28 °C may at least be partially orchestrated by the down-regulation of MTC enzymes and concomitant cycle perturbation. In line with this, foliar treatment of these plants with methionine restored accumulation of MTC metabolites and subverted the susceptibility to PVY at elevated temperature. These data are discussed in the context of the major function of the MTC in transmethylation processes.     

The timing of alpha-gustducin expression during cell renewal in rat vallate taste buds

The G protein subunit alpha-gustducin is expressed in a subset of light (Type II) but not in dark (Type I) cells in rat vallate taste buds. The thymidine analogue 5-bromo-2'-deoxyuridine (BrdU) is incorporated into DNA during the S-phase of the cell cycle and can be used to determine the time of origin of a cell. In this study, 31 rats were injected with BrdU (50 mg/kg i.p.) and perfused at various times, from 2.5 to 10.5 days, following BrdU administration. Vallate papillae were embedded in polyester wax, cut into 4 microm transverse sections, and characterized with antibodies to BrdU and alpha-gustducin. Sections were processed for indirect immunofluorescence or with an immunoperoxidase procedure. From immunoperoxidase material on 21 rats, counts of alpha-gustducin- and BrdU-labeled cells were obtained from 300-800 taste bud profiles at each survival time; a total of 4122 taste bud profiles were examined. Cells with nuclei immunoreactive for BrdU occurred within the taste buds at 2.5 days and double-labeled cells were clearly evident at 3.5 days; a small number of double-labeled cells were seen as early as 2.5 days. Double-labeled cells reached a peak at 6.5 days and did not decline significantly by 10.5 days. Cells labeled for BrdU but not alpha-gustducin peaked at 5.5 days and showed a significant decline by 8.5 days. These latter cells included light cells not expressing alpha- gustducin and dark cells, which have previously been shown to have a shorter life span than light cells. These data suggest that expression of alpha-gustducin appears very early in a cell's life span and that these cells are longer lived than many of the cells that do not express this G protein.      

Preferential DNA photocleavage potency of Zn(II) over Ni(II) derivatives of carboxymethyl tetracationic porphyrin: the role of the mode of binding to DNA

The porphyrin-based photosensitizers capable of binding to DNA are perspective drug candidates. Here we report the interactions with calf thymus DNA of 5,10,15,20-tetrakis(N-carboxymethyl-4-pyridinium)porphyrin (P1) and its derivatives containing Zn(II) or Ni(II) in the coordination sphere. These interactions were studied with absorption and circular dichroism spectroscopy. NiP1 and ZnP1 formed different types of complexes with DNA. NiP1 intercalated into the double helix, whereas ZnP1 bound the DNA groove. Compound P1 displayed both binding modes. The ZnP1-DNA binding constant was approximately three times smaller than the respective values for P1-DNA and NiP1-DNA complexes. Light induced degradation of the reactive oxygen species (ROS) trap 1,3-diphenylisobenzofuran in the presence of P1 and its metal derivatives revealed that NiP1 was a weaker photooxidative agent, whereas P1 and ZnP1 generated ROS to similar extents. Nevertheless, the DNA photodamaging effect of ZnP1 was the most pronounced. Illumination of the supercoiled plasmid caused single-strand DNA photocleavage in the presence of P1 and ZnP1; double strand breaks were detectable with micromolar concentrations of ZnP1. The concentration of ZnP1 required for plasmid photonicking was two times smaller than that of P1 and ~20 times lower than that for NiP1. Thus, the modes of P1, NiP1 and ZnP1 binding to DNA determine the differential photodamaging potency of these porphyrins. A greater accessibility to the solvent of the groove binder ZnP1, compared to the shielded intercalator NiP1 and the intercalated P1 molecules, allows for an efficient local generation of ROS followed by DNA photocleavage.