Тransplastomic tobacco plants producing the hydrophilic domain of the sheep pox virus coat protein L1R

Sheep pox has a wide geographical range of distribution and poses a threat to sheep breeding worldwide, as the disease is highly contagious and is accompanied by large economic losses. Vaccines based on live attenuated virus strains are currently being used for prevention of this disease. Such vaccines are effective, but potentially dangerous because of the possible virus reversion to a pathogenic state. The development of safe recombinant subunit vaccines against sheep pox is very relevant. The high ploidy level of the plant chloroplasts makes it possible to obtain large quantities of foreign proteins. The purpose of this study was to create transplastomic Nicotiana tabacum plants producing one of the candidate vaccine proteins of sheep pox virus L1R. A vector containing a deletion variant of the SPPV_56 gene, which encodes the N-terminal hydrophilic part of the viral coat protein L1R, was constructed to transform tobacco plastids. It provides integration of the transgene into the trnG/trnfM region of the chloroplast tobacco genome by homologous recombination. Spectinomycin-resistant tobacco lines were obtained by biolistic gun-mediated genetic transformation. PCR analysis in the presence of gene-specific primers confirmed integration of the transgene into the plant genome. Subsequent Northern and Western blot analysis showed the gene expression at the transcriptional and translational levels. The recombinant protein yields reached up to 0.9 % of total soluble protein. The transplastomic plants displayed a growth retardation and pale green leaf color compared to the wild type, but they developed normally and produced seeds. Southern blot analysis showed heteroplasmy of the plastids in the obtained plants due to recombination events between native and introduced regulatory plastid DNA elements. The recombinant protein from plant tissue was purified using metal affinity chromatography. Future research will be focused on determining the potential of the chloroplast-produced protein to induce neutralizing antibodies against SPPV strains

UV Curable Self-Healing Structural Epoxy Composite Materials Interfacial Polycondensation Microencapsulation of Healing Agent and Photo-Initiator

The ability of polymeric coatings to self-heal itself from mechanical damage is explored in this paper. Polymeric coatings with self-healing property is one of the important aspects in modern science. It can be used in industries such as oil industry (protection against corrosion), mechanical engineering, aircraft, etc. The polyurethane (PU) microparticles were synthesized on the basis of polypropyleneglycol (PPG) and toluene diisocyanate (TDI) with a method of interfacial polycondensation at the interface water-benzene. Further to study the surface morphology of the microcapsules with healing agent (trimethylolpropanetriacrylate– TMPTA) obtained PU was applied the method of scanning electron and atomic force microscopy. The PU microparticles hollow inside have regular spherical shape with a diameter of 5-10 µm with a dense and smooth polymerics shell. The resulting polyimide–polyurethane (PI–PU) composites have high potential to regenerate damaged surfaces not only on the surface and also in the volume of composite within several minutes

ARC‐1, a sequence element complementary to an internal 18S rRNA segment, enhances translation efficiency in plants when present in the leader or intercistronic region of mRNAs

The sequences of different plant viral leaders with known translation enhancer ability show partial complementarity to the central region of 18S rRNA. Such complementarity might serve as a means to attract 40S ribosomal subunits and explain in part the translation‐enhancing property of these sequences. To verify this notion, we designed β‐glucuronidase (GUS) mRNAs differing only in the nature of 10 nt inserts in the center of their 41 base leaders. These were complementary to consecutive domains of plant 18S rRNA. Sucrose gradient analysis revealed that leaders with inserts complementary to regions 1105-1114 and 1115-1124 (‘ARC‐1') of plant 18S rRNA bound most efficiently to the 40S ribosomal subunit after dissociation from 80S ribosomes under conditions of high ionic strength, a treatment known to remove translation initiation factors. Using wheat germ cell‐free extracts, we could demonstrate that mRNAs with these leaders were translated more than three times more efficiently than a control lacking such a complementarity. Three linked copies of the insert enhanced translation of reporter mRNA to levels comparable with those directed by the natural translation enhancing leaders of tobacco mosaic virus and potato virus Y RNAs. Moreover, inserting the same leaders as intercistronic sequences in dicistronic mRNAs substantially increased translation of the second cistron, thereby revealing internal ribosome entry site activity. Thus, for plant systems, the complementary interaction between mRNA leader and the central region of 18S rRNA allows cap‐independent binding of mRNA to the 43S pre‐initiation complex without assistance of translation initiation factor

Generation of Magnetic Field by Combined Action of Turbulence and Shear

The feasibility of a mean-field dynamo in nonhelical turbulence with superimposed linear shear is studied numerically in elongated shearing boxes. Exponential growth of magnetic field at scales much larger than the outer scale of the turbulence is found. The charateristic scale of the field is l_B ~ S^{-1/2} and growth rate is gamma ~ S, where S is the shearing rate. This newly discovered shear dynamo effect potentially represents a very generic mechanism for generating large-scale magnetic fields in a broad class of astrophysical systems with spatially coherent mean flows.Comment: 4 pages, 5 figures; replaced with revised version that matches the published PR

ПЕРСПЕКТИВЫ НАНОСТРУКТУРИРОВАННЫХ МАТЕРИАЛОВ И МЕТОД СОЗДАНИЯ НАНОКЛАСТЕРНОГО КОМПОЗИТА

Nano-scale structures of constructional materials provide  unique possibilities for obtaining a new level of properties: high strength, hardness, wear-resistance at rather high plasticity. An increase in ceramics and inter-metallic compound plasticity gives wide prospects for their usage in constructions. Development of methods for obtaining  3D (massive) nano-crystal blanks with uniform structure along blank section, without pores, micro-cracks and other structure defects is an actual problem and its solution will make it possible to expand an application of constructional nano-materials.Наноразмерные структуры конструкционных материалов дают уникальные возможности для получения нового уровня свойств: высокой прочности, твердости, износостойкости при достаточно высокой пластичности. Повышение пластичности керамики и интерметаллидов открывает большие перспективы для их использования в конструкциях.Разработка методов получения объемных (массивных) нанокристаллических заготовок с равномерной структурой по сечению заготовки, без пор, микротрещин и других дефектов структуры – актуальная задача, решение которой позволит расширить применение наноматериалов конструкционного назначения

Two-dimensional model of thermal smoothing of laser imprint in a double-pulse plasma

The laser prepulse effect on the thermal smoothing of nonuniformities of target illumination is studied by means of a two-dimensional Lagrangian hydrodynamics simulation, based on the parameters of a real experiment. A substantial smoothing effect is demonstrated for the case of an optimum delay between the prepulse and the main heating laser pulse. The enhancement of the thermal smoothing effect by the laser prepulse is caused by the formation of a long hot layer between the region of laser absorption and the ablation surface. A comparison with experimental results is presented

Fluctuation dynamo and turbulent induction at low magnetic Prandtl numbers

This paper is a detailed report on a programme of simulations used to settle a long-standing issue in the dynamo theory and demonstrate that the fluctuation dynamo exists in the limit of large magnetic Reynolds number Rm>>1 and small magnetic Prandtl number Pm<<1. The dependence of the critical Rm_c vs. the hydrodynamic Reynolds number Re is obtained for 1<Re<6700. In the limit Pm<<1, Rm_c is ~3 times larger than for Pm>1. The stability curve Rm_c(Re) (and, it is argued, the nature of the dynamo) is substantially different from the case of the simulations and liquid-metal experiments with a mean flow. It is not as yet possible to determine numerically whether the growth rate is ~Rm^{1/2} in the limit Re>>Rm>>1, as should be the case if the dynamo is driven by the inertial-range motions. The magnetic-energy spectrum in the low-Pm regime is qualitatively different from the Pm>1 case and appears to develop a negative spectral slope, although current resolutions are insufficient to determine its asymptotic form. At 1<Rm<Rm_c, the magnetic fluctuations induced via the tangling by turbulence of a weak mean field are investigated and the possibility of a k^{-1} spectrum above the resistive scale is examined. At low Rm<1, the induced fluctuations are well described by the quasistatic approximation; the k^{-11/3} spectrum is confirmed for the first time in direct numerical simulations.Comment: IoP latex, 27 pages, 25 figures, 3 tables. Accepted by New J. Physic

Evaluation of the technological properties of down based on the technology of dying the down of goats of coarse-haired, down and wool breeds

The article is devoted to the study and assessment of the technological properties of down based on the technology of dyeing down from goat wool from various genotypes of goats of the republic. The dyeing was carried out under laboratory conditions with Italian dyes. The dependence of the color intensity for downy fibers is described by polynomial equations of the second and third degree. It has been shown that goat down fibers have good dyeing ability, dyeing uniformity and show good dyeing performance in standard modes

Constructing the constitutively active ribosomal protein S6 kinase 2 from <i>Arabidopsis thaliana</i> (AtRPS6K2) and testing its activity <i>in vitro</i>

Ribosomal protein S6 (RPS6) is the only phosphorylatable protein of the eukaryotic 40S ribosomal subunit. Ribosomes with phosphorylated RPS6 can selectively translate 5’TOP-(5’-terminal oligopyrimidine)-containing mRNAs that encode most proteins of the translation apparatus. The study of translational control of 5’TOP-mRNAs, which are preferentially translated when RPS6 is phosphorylated and cease to be translated when RPS6 is de-phosphorylated, is particularly important. In Arabidopsis thaliana, AtRPS6 is phosphorylated by kinase AtRPS6K2, which should in turn be phosphorylated by upper level kinases (AtPDK1 – at serine (S) 296, AtTOR – at threonine (T) 455 and S437) for full activation. We have cloned AtRPS6K2 cDNA gene and carried out in vitro mutagenesis replacing codons encoding S296, S437 and T455 by triplets of phosphomimetic glutamic acid (E). After the expression of both natural and mutated cDNAs in Escherichia coli cells, two recombinant proteins were isolated: native AtRPS6K2 and presumably constitutively active AtRPS6K2(S296E, S437E, T455E). The activity of these variants was tested in vitro. Both kinases could phosphorylate wheat (Triticum aestivum L.) TaRPS6 as part of 40S ribosomal subunits isolated from wheat embryos, though the non-mutated variant had less activity than phosphomimetic one. The ability of recombinant non-mutated kinase to phosphorylate TaRPS6 can be explained by its phosphorylation by bacterial kinases during the expression and isolation steps. The phosphomimetically mutated AtRPS6K2(S296E, S437E, T455E) can serve as a tool to investigate preferential translation of 5’TOP-mRNAs in wheat germ cell-free system, in which most of 40S ribosomal subunits have phosphorylated TaRPS6. Besides, such an approach has a biotechnological application in producing genetically modified plants with increased biomass and productivity through stimulation of cell growth and division

Evidence that phosphorylation of the alpha-subunit of eIF2 does not essentially inhibit mRNA translation in wheat germ cell-free system.

A mechanism based on reversible phosphorylation of the α-subunit of eukaryotic initiation factor 2 (eIF2α) has been confirmed as an important regulatory pathway for inhibition of protein synthesis in mammalian and yeast cells, while plants constitute the significant exception. We studied the induction of TaeIF2α phosphorylation in germinated wheat (Triticum aestivum) embryos subjected to different adverse conditions. Data confirmed that formation of TaeIF2(αP) was not a general response, as no phosphorylation was observed under salt, oxidative or heat stress. Nevertheless, treatment by salicylic acid, UV-light, cold shock and histidinol did induce phosphorylation of TaeIF2α of wheat, as has been established previously for AteIF2α in Arabidopsis (Arabidopsis thaliana). Influence of TaeIF2α phosphorylation on translation of reporter mRNA with different 5′-untranslated regions (5′UTRs) was studied in wheat germ cell-free system (WG-CFS), in which TaeIF2α was first phosphorylated either by heterologous recombinant human protein kinase, HsPKR (activated by double-stranded (ds)RNA), or by endogenous protein kinase TaGCN2 (activated by histidinol). Pre-treatment of WG-CFS with HsPKR in the presence of dsRNA or with histidinol resulted in intense phosphorylation of TaeIF2α; however, the translation levels of all tested mRNAs decreased by only 10–15% and remained relatively high. In addition, factor OceIF2 from rabbit (Oryctolagus cuniculus) bound GDP much more strongly than the homologous factor TaeIF2 from wheat germ. Furthermore, factor OceIF2B was able to stimulate guanine nucleotides exchange (GDP→GTP) on OceIF2 but had no effect on the similar exchange on TaeIF2. These results suggest that the mechanism of stress response via eIF2α phosphorylation is not identical in all eukaryotes and further research is required to find and study in detail new plant-specific mechanisms that may inhibit overall protein synthesis in plants under stress