Selection of behavioral test parameters for estimation of typological features of rat behavior

Behavior of 86 rats was examined in three behavioral tests, i.e., open field, forced swimming and emotionality by F. King. The results of statistical analysis of all the indices obtained with application of factor analysis suggest that the three tests characterize four relatively independent behavioral components: emotionality, locomotor-exploratory activity, olfactory performance, and resistance to adverse emotional factors. A contribution of each measured parameter to the above components was estimated. Such an approach makes it possible to reasonably select most important behavioral features when estimating locomotor activity and emotionality of animals.     

Nucleoside Diphosphate Kinase Is a Possible Component of the Ethylene Signal Transduction Pathway

In etiolated seedlings of Pisum sativum and leaves of Arabidopsis thaliana, in vivo ethylene treatment resulted in an increase in in vitro phosphorylation of 17 kD (P. sativum) or 16 and 17 kD (A. thaliana) polypeptides. These polypeptides were identified as nucleoside diphosphate kinase (NDPK) based on both biochemical properties and interaction with antibodies against NDPK from P. sativum. Using the receptor-directed antagonist of ethylene action 2,5-norbornadiene and the ethylene-insensitive mutants of A. thaliana etr1-1 and eti5, ethylene specificity and receptor dependence of NDPK phosphorylation have been demonstrated. In pea epicotyls, ethylene treatment also led to increase in nucleoside transferase activity unlike in A. thaliana leaves. The increases in nucleoside transferase activity and NDPK phosphorylation were very rapid and transient. The results suggest a role for NDPK as a possible component of the ethylene signal transduction chain.     

Phage sensitivity and host range of Rhizobium strains isolated from root nodules of temperate legumes

Twenty-five Rhizobium strains were isolated from root nodules of Astragalus spp. (10), Hedysarum alpinum (7), Glycyrrhiza pallidiflora (3) and Ononis arvensis (5). The sensitivity of these strains to bacteriophages of Rhizobium loti, R. meliloti, R. galegae and R. leguminosarum was studied. Phages specific to R. loti strains were shown to induce the phage lysis of several Astragalus, Hedysarum and Ononis rhizobia. Ten R. loti strains tested for nodulation abilities on the plant hosts under investigation were able to develop nitrogen-fixing nodules on the Ononis arvensis roots. On the other hand, rhizobia from Ononis and Glycyrrhiza could form an effective symbiosis with Lotus corniculatus plants, so these bacteria are considered to belong to the Rhizobium loti taxon. Bacterial strains isolated from Astragalus and Hedysarum were observed to cross-nodulate their plant hosts as well as Oxytropis campestris, Glycyrrhiza uralensis and Ononis arvensis plants, whereas they could not nodulate Lotus plants. It is concluded that these Rhizobium strains comprise a cross-inoculation group related to Rhizobium loti. ei]{gnR O D}{fnDixon}     

Enhanced competitiveness for nodulation of Medicago sativa by Rhizobium meliloti transconjugants harbouring the root-inducing plasmids of Agrobacterium rhizogenes strain 15834

Abstract The root-inducing plasmid of Agrobacterium rhizogenes strain 15834 marked with transposon Tn5-mob with a helper plasmid RP4-4 was mobilized into nitrogen-fixing Rhizobium meliloti strain CIAM 1759. The resulting transconjugants did not induce ‘hairy’ root syndrome but developed nitrogen-fixing nodules on alfalfa. Among the 9 transconjugants tested, 6 strains had increased nodulation rates. The competitiveness of 2 of these R. meliloti (pRi) strains was significantly enhanced as compared with the parent strain CIAM 1759; this was confirmed both in tube and in pot tests.     

Localization of metallocarboxypeptidase D in AtT-20 cells. Potential role in prohormone processing.

Carboxypeptidase D (CPD) is a recently discovered metallocarboxypeptidase that is predominantly located in the trans-Golgi network (TGN), and also cycles between the cell surface and the TGN. In the present study, the intracellular distribution of CPD was examined in AtT-20 cells, a mouse anterior pituitary-derived corticotroph. CPD-containing compartments were isolated using antibodies to the CPD cytosolic tail. The immunopurified vesicles contained TGN proteins (TGN38, furin, syntaxin 6) but not lysosomal or plasma membrane proteins. The CPD-containing vesicles also contained neuropeptide-processing enzymes and adrenocorticotropic hormone, a product of proopiomelanocortin proteolysis. Electron microscopic analysis revealed that CPD is present within the TGN and immature secretory granules but is virtually absent from mature granules, suggesting that CPD is actively removed from the regulated pathway during the process of granule maturation. A second major finding of the present study is that a soluble truncated form of CPD is secreted mainly via the constitutive pathway in AtT-20 cells, indicating that the lumenal domain does not contain signals for the sorting of CPD to mature secretory granules. Taken together, these data are consistent with the proposal that CPD participates in the processing of proteins within the TGN and immature secretory vesicles.     

Molecular modeling of the reactive configuration of peroxidized lipid and α-tocopherol in the membrane

The mutual arrangement of a phospholipid molecule containing a peroxyl radical and a molecule of membrane-acting antioxidant α-tocopherol (vitamin E) in the lipid bilayer has been studied by molecular dynamics simulation. The geometry of molecules in the membrane is revealed at which the hydrogen atom can be transferred from the exocyclic hydroxyl of α-tocopherol to the peroxyl lipid radical. It is shown that, under equilibrium conditions, the peroxidized fatty acid segment rises nearer to the polar surface of the membrane, while α-tocopherol submerges into the hydrophobic part of the lipid bilayer.     

Small cooperative activity of old rat hepatocytes may depend on composition of the intercellular medium

Ultradian oscillations of protein synthesis were used as a marker of hepatocyte synchronous cooperative activity producing a common rhythm in vitro; amplitude of the rhythm defines expression of the cell cooperation. Dense synchronous and sparse non-synchronous rat hepatocyte cultures on slides in a serum-free incubation medium 199 supplemented with 0.2 mg/ml albumin and 0.5 microg/ml insulin have been studied. The amplitude of the rhythm averaged approximately 2x in dense cultures of young (3 month old) rats than in old (2 year old) rats. But some cultures of young rats had the amplitude patterns similar to cultures of old rats, and vice versa. Addition to the medium of either 0.3 microM bovine brain gangliosides or 2 microM phenylephrine resulted in increase of the oscillation amplitude in dense cultures of old rats to the level inherent in young ones. Addition to the medium of 10% rat blood serum in non-synchronous sparse cultures from young rats resulted in detection of a protein synthetic rhythm. Although after serum from young rats, the rhythm expression was high, the rhythm after serum from old rats had been given was weak. Addition of gangliosides to old-rat serum resulted in synchronization of sparse cultures with amplitudes inherent of young-rat serum. The data tend to the conclusion that cell cooperation depends to a greater extent on the composition of the medium rather than on the age of the cell or animal.     

Possible states of photosystem II reaction center and thermoluminescence of the higher plants. I. Analysis of thermoluminescence models and their applicability to the description of experimental data

A method for the deconvolution of experimental glow curves into overlapping bands and determination of the activation energies for these bands is proposed. The model includes the S-states of the water-splitting complex, tyrozine Z and P680 on the donor side, pheophytine, primary and secondary quinone acceptors on the acceptor side, and takes into account the connection between different states of the reaction center complex. The rate constants of forward electron transport and the activation energies of backward reactions of electron transfer in photosystem II reaction center, included into the model, are estimated from the known experimental data using the proposed approach.     

Isolation and effects of inducing factors secreted by the lens epithelium cells

Our previous studies showed that, unlike tissue extracts, the cells of living organs secrete substances capable of inducing the same organ rudiments in the early gastrula ectoderm (EGE). In this work, the molecular nature of these substances was studied. The porcine lens epithelium was chosen for the initial analysis. When cultivated, this epithelium secreted a mixture of proteins, which were separated by gel-filtration. Both the total protein mixture and its individual fractions were tested for their inducing capacity using the early gastrula ectoderm of Rana temporaria. Unexpected results were obtained, which indicated that (a) the mixture of native proteins secreted by lens epithelium has a selective inducing capacity differing from those of individual fractions isolated from this mixture and (b) each fraction has a specific effect, but all of them cause the induction of neural tissue or sensory organs. These results (obtained for the first time) suggest that the inducing capacity of individual protein fractions is wider than that of the total protein mixture secreted by lens epithelium. This fact raises a question concerning the relationships between the mechanisms underlying the corresponding inducing effects.     

Physico-chemical and microbiological characteristics of groundwater from observation boreholes of a deep radioactive liquid waste repository

A radioactive liquid waste repository was found to be a habitat of the rich microbial community with a high catabolic potential. Groundwater from a depth of 162-189 m contained aerobic saprotrophic and anaerobic fermentative, sulfate-reducing, and denitrifying bacteria. Nitrate-reducing bacteria residing in this groundwater were isolated in pure cultures. Based on the results of their physiological studies, 16S rRNA sequencing, and phylogenetic analysis, the microorganisms isolated were ascribed to one phylogenetic branch, the gamma-subclass of gram-negative bacteria. Among six isolates, four belonged to the genus Acinetobacter, whereas two others belonged to the genera Comamonas and Aeromonas. The data obtained indicate that the microflora of the repository can exert a certain effect on the chemical composition of the formation fluids and bearing rocks, as well as on the migration of radionuclides.