Recombinant human peroxiredoxin VI: preparation and protective properties in vitro

cDNA of human peroxiredoxin VI, one of the recently discovered novel antioxidant proteins, was expressed in Escherichia coli cells. The expression product was obtained in water-soluble form and purified by a two-step chromatographic procedure using DEAE-Sepharose and Sephacryl S-200. According to CD data, the polypeptide chain of the recombinant human peroxiredoxin VI contains 40% -helical region and 30% -structure, which is the same as for native rat peroxiredoxin VI. The protective properties of the recombinant protein determined as its ability to prevent the inactivation of glutamine synthetase from E. coli in a model oxidation system were comparable with the protective properties of native rat peroxiredoxin VI.     

Effect of developing Sarcocystis muris tissue cysts on ultrastructural change of murine muscle fibers

A study was made of the influence exerted by developing sarcocysts of Sarcocystis muris on the ultrastructural organization of muscle fibres, both harbouring the sarcocysts (HSM) and sarcocyst-free (SFM), from skeletal muscles of experimentally infected mice. Muscle fibres of non-infected mice of the same age served as a control. Mice were sacrificed 6 months following feeding S. muris oocysts (or sporocysts). The developing sarcocysts seriously destroyed HSM: their myofilaments were no hold in register, cross-bridges almost entirely disappeared, M-lines and Z-disks looked as broken structures. The majority of actin myofilaments were arranged along myosin myofilaments as discrete units. The host cell sarcoplasm was packed with numerous vacuoles of different form and size. Compared to muscle fibres in the control, SFM of infected mice also displayed an obvious ultrastructural alteration. On the periphery of SFM, some destroyed sarcomeres with swollen myofilaments were noticed whose cross-bridges were totally lacking. In other extreme areas myosin and actin myofilaments were disintegrated into thin straightened filaments 2.0-2.5 nm in diameter. It is supposed that HSM and SFM of the infected mice may experience different kinds of influence on the part of the developing intracellular parasite (sarcocyst). And it dos not seem unlikely that various biologically active substances, produced by the parasite, may be vesicle transported to SFN through the endomysium space.     

Inheritance of greenbug resistance in several forms of grain sorghum and sudangrass

The inheritance of resistance against the Krasnodar population of common greenbug Schizaphis graminum Rond. was analyzed in nine accessions of grain sorghum and sudangrass. The dominant gene of cultivar Capbam (k-455, United States) was effective against some greenbug clones and differed from the Sgr1–Sgr11 resistance genes. The gene was designated as Sgr12. The cultivar Capbam was proposed for use as a differentiator in population genetic studies in S. graminum. The cultivar Sarvasi (k-3852, Hungary) contains not only the dominant Sgr1 gene, but also a recessive gene (most likely Sgr2), which is effective against some greenbug clones. Grain sorghum accessions k-928 and k-929 (Gugara Belaya, western China) each carry two highly effective dominant resistance genes, which differ from Sgr1–Sgr4, Sgr6, Sgr9, and Sgr10. In addition, the resistance genes of accession k-929 differ from the Sgr5 gene. Accession k-928 proved to contain an additional dominant resistance gene, which is expressed in response to some greenbug clones. The gene was designated as Sgr13. Sudangrass accessions k-100 and k-122 (Ukraine) each carry two dominant resistance genes. Accessions k-62, k-99 (Ukraine), and k-96 (Russia) each carry one dominant and one recessive resistance gene. The dominant resistance genes that are expressed in the cultivar Odesskaya 25 (k-122) in response to infestation with some clones from the natural greenbug population were designated as Sgr14 and Sgr15.     

Myctophid (Myctophidae) Abundance and Ecology in the Gulf of Alaska in Winter

Russian Journal of Marine Biology - The distribution and abundance of four common myctophid fish species in the upper epipelagic layer of the northeastern North Pacific in winter were analyzed...     

The taxonomic status and relationships of stichaeid fish of the <Emphasis Type="Italic">Opisthocentrus,Pholidapus</Emphasis>, and <Emphasis Type="Italic">Askoldia</Emphasis> Genera (Perciformes: Stichaeidae)

The taxonomic status and relationships of the Askoldia, Pholidapus, and Opisthocentrus genera of the subfamily Opisthocentrinae are discussed based on comparative morphological and molecular genetic analysis. Isolation of the Pholidapus from the Opisthocentrus and the greater similarity of the former with the Askoldia were revealed. Morphological and genetic differences could not allow one to consider the Pholidapus as being within the Opisthocentrus. O. ocellatus and O. tenuis were closer within the Opisthocentrus and O. zonope was significantly different from these two species.     

The Novel Approach to the Protein Design: Active Truncated Forms of Human 1-CYS Peroxiredoxin

Abstract

The object of the present study is the verification of a new approach to the design of the active truncated forms of enzymes. The method is based on a new way of investigating the protein sequences—the ANalysis of Informational Structure (ANIS). The analysis of informational structure allows to determine the hierarchically organized structures (IDIC-trees) formed by the sites with the Increased Degree of Informational Coordination between residues. The proposed approach involves the consequent removal of the fragments corresponding to the individual IDIC-trees from the wild-type enzyme sequences. The described procedure was applied to the design of the active truncated form of human 1-CYS peroxiredoxin (PrxVI). Two variants of the PrxVI truncated sequences were proposed according to ANIS method. These truncated forms of the enzyme were expressed in E. coli and purified. The respective antioxidant activities were measured. It was shown that one of the truncated recombinant proteins retains more than 90% of the wild-type PrxVI enzymatic activity. According to the results of our study we can assume that ANIS method can be an effective tool for the design of the active truncated forms of the enzymes or the chimeric proteins which combine the enzymatic activities of their wild-type prototypes.     

Structure of multi-species ant assemblages (Hymenoptera,Formicidae) in the Mountain Crimea

The multi-species ant assemblages were studied in the Crimea Mountains, in 9 types of plant associations in the plateau pastures as well as on the southern and northern slopes of the Main Range. A list of 18 ant species with data on their distribution in biotopes and also layers and the structure of their foraging territories is given. The hierarchical organization of multi-species ant assemblages and different strategies of nest location of the influents depending on the dominant species and its territoriality were investigated. Territoriality of each dominant species was determined by the frequency of foraging areas without nests of other species. Depending on dominant territoriality and the number of dominant species, the following classification of multi-species assemblages is proposed. (1) Monodominant assemblages with weakly expressed territoriality of the dominant species. Low density of the workers of Camponotus aethiops in the foraging territory determines weak interactions with influent species. The settling pattern of the influents shows no evident dependence on the dominant. Weakly expressed territoriality of the dominant allows non-territorial species to exist on the dominant’s territory. Such species were not found in other types of ant assemblages. (2) Monodominant assemblages with strongly expressed territoriality of the dominant species. The settling pattern of the influents shows the subordinate species to avoid those of higher ranks in the hierarchy, thus decreasing the probability of conflicts. The influents settle in the neutral zones as well as in the foraging territory of the dominant, so as to reduce competition with the subdominant species Formica cunicularia. Such a strategy reduces the probability of interspecific conflicts in biotopes with fewer vegetation layers than in the forests. (3) Bidominant assemblages with a variable dendrobiont dominant are typical among forest assemblages. Coexistence of two dominant species is possible when foraging of one of them is completely or partly restricted to one vegetation layer. The subdominant species avoid settling in the foraging territory of the dominant that occupies the same layer. When the dendrobiont dominant Crematogaster schmidti drops out of the assemblage, it (and its role in the assemblage) is replaced by other dendrobiont species Lasius emarginatus which otherwise acts as the 1st order subdominant in C. schmidti assemblages. (4) Polydominant assemblages are characterized by the presence of as many as 3 dominant species, namely Crematogaster schmidti, Camponotus aethiops, and Plagiolepis tauricus. The coexistence of the dominants is possible due to use of different layers (one species is a dendrobiont, the other two are herpeto-hortobionts), different activity periods (round-the-clock in Crematogaster schmidti, night in Camponotus aethiops, and daytime in P. tauricus), and different size classes of the workers (3rd, 5th, and 1st, respectively). The different size classes of workers reduce competition for food. Thus, when the number of dominant species in the assemblage increases, so does the number of mechanisms facilitating their coexistence.