Mice in Bion-M 1 Space Mission: Training and Selection

After a 16-year hiatus, Russia has resumed its program of biomedical research in space, with the successful 30-day flight of the Bion-M 1 biosatellite (April 19–May 19, 2013). The principal species for biomedical research in this project was the mouse. This paper presents an overview of the scientific goals, the experimental design and the mouse training/selection program. The aim of mice experiments in the Bion-M 1 project was to elucidate cellular and molecular mechanisms, underlying the adaptation of key physiological systems to long-term exposure in microgravity. The studies with mice combined in vivo measurements, both in flight and post-flight (including continuous blood pressure measurement), with extensive in vitro studies carried out shortly after return of the mice and in the end of recovery study. Male C57/BL6 mice group housed in space habitats were flown aboard the Bion-M 1 biosatellite, or remained on ground in the control experiment that replicated environmental and housing conditions in the spacecraft. Vivarium control groups were used to account for housing effects and possible seasonal differences. Mice training included the co-adaptation in housing groups and mice adaptation to paste food diet. The measures taken to co-adapt aggressive male mice in housing groups and the peculiarities of “space” paste food are described. The training program for mice designated for in vivo studies was broader and included behavioral/functional test battery and continuous behavioral measurements in the home-cage. The results of the preliminary tests were used for the selection of homogenous groups. After the flight, mice were in good condition for biomedical studies and displayed signs of pronounced disadaptation to Earth''s gravity. The outcomes of the training program for the mice welfare are discussed. We conclude that our training program was effective and that male mice can be successfully employed in space biomedical research.     

Spatial Structure and Dynamics of a Pulsed Arc Discharge in Vacuum

Plasma Physics Reports - The process of switching a short vacuum gap using an auxiliary discharge over the surface of a dielectric is studied by the high-speed recording of images of the plasma in...     

Life history variation in Barents Sea fish: implications for sensitivity to fishing in a changing environment

• Under exploitation and environmental change, it is essential to assess the sensitivity and vulnerability of marine ecosystems to such stress. A species' response to stress depends on its life history. Sensitivity to harvesting is related to the life history “fast–slow” continuum, where “slow” species (i.e., large, long lived, and late maturing) are expected to be more sensitive to fishing than “fast” ones. We analyze life history traits variation for all common fish species in the Barents Sea and rank fishes along fast–slow gradients obtained by ordination analyses. In addition, we integrate species' fast–slow ranks with ecosystem survey data for the period 2004–2009, to assess life history variation at the community level in space and time. Arctic fishes were smaller, had shorter life spans, earlier maturation, larger offspring, and lower fecundity than boreal ones. Arctic fishes could thus be considered faster than the boreal species, even when body size was corrected for. Phylogenetically related species possessed similar life histories. Early in the study period, we found a strong spatial gradient, where members of fish assemblages in the southwestern Barents Sea displayed slower life histories than in the northeast. However, in later, warmer years, the gradient weakened caused by a northward movement of boreal species. As a consequence, the northeast experienced increasing proportions of slower fish species. This study is a step toward integrating life history traits in ecosystem‐based areal management. On the basis of life history traits, we assess the fish sensitivity to fishing, at the species and community level. We show that climate warming promotes a borealization of fish assemblages in the northeast, associated with slower life histories in that area. The biology of Arctic species is still poorly known, and boreal species that now establish in the Arctic are fishery sensitive, which calls for cautious ecosystem management of these areas.

     

Modeling of protein spatial structure using tritium planigraphy

The results of protein spatial structure modeling using the tritium planigraphy technique are presented. The knowledge of 3D structure of macromolecules is obligatory for understanding the basic mechanisms of interaction in biological systems and complex technological processes. Known limitations of the X-ray analysis (crystal state) and NMR (molecular weight) make it necessary to seek new approaches to modeling the spatial structure of proteins. Semiempirical tritium planigraphy is one of these approaches. The method is based on bombardment of the object with a beam of hot tritium atoms (E _at ≥ 0.3 eV) and computer simulation. On the example of proteins of different structural classes, we show that this integrated approach can yield a 3D model well consistent with the X-ray data. An important factor is the sequence of searching for contacts between secondary structure elements: the best fit with the native structure is achieved by assembling the elements from the N- to the C-terminus of the polypeptide chain.     

A new species of Heth Cobb, 1898 (Nematoda: Rhigonematida: Hethidae) from an Australian millipede (Myriapoda: Diplopoda: Spirostreptida)

Abstract

A new species of nematode, Heth baudini sp. n. from a diplopod (Spirostreptida: Iulomorphidae Verhoeff, 1924) collected in Queensland, Australia, is described and illustrated. The cephalic and cervical cuticular ornamentation of females of H. baudini sp. n. is similar to those of South-East Asian and Australasian Heth species. Heth baudini sp. n. females are particularly close to Heth taynguyeni from Vietnam but can be distinguished by the shape of the lateral lappets, which in H. taynguyeni limit the trapezium-shaped region of smooth cuticle unlike the elliptical region in H. baudini sp. n., and by the presence of lateral spines only half the size. The cuticle of the H. baudini sp. n. is finely annulated along the entire body, whereas H. taynguyeni has broader rings behind the first pair of lateral spines, each consisting of five or six narrower rings separated from each other by deeper furrows. Males of H. baudini sp. n. are characterised by the presence of a bursa-like fold on the tail and can be distinguished from other species of the genus by the presence of somatic papillae embedded into the bursal fold.     

Differences in spatial structures of the influenza virus M1 protein in crystal, solution and virion

Spatial structure of the influenza virus A/Puerto Rico/8/34 (PR8, subtype H1N1) M1 protein in a solution and composition of the virion was studied by tritium planigraphy technique. The special algorithm for modeling of the spatial structure is used to simulate the experiment, as well as a set of algorithms predicting secondary structure and disordered regions in proteins. Tertiary structures were refined using the program Rosetta. To compare the structures in solution and in virion, also used the X-ray diffraction data for NM-domain. The main difference between protein structure in solution and crystal is observed in the contact region of N- and M-domains, which are more densely packed in the crystalline state. Locations include the maximum label is almost identical to the unstructured regions of proteins predicted by bioinformatics analysis. These areas are concentrated in the C-domain and in the loop regions between the M-, N-, and C-domains. Analytical centrifugation and dynamic laser light scattering confirm data of tritium planigraphy. Anomalous hydrodynamic size, and low structuring of the M1 protein in solution were found. The multifunctionality of protein in the cell appears to be associated with its plastic tertiary structure, which provides at the expense of unstructured regions of contact with various molecules-partners.     

The effect of auxins, time exposure to auxin and genotypes on somatic embryogenesis from mature embryos of wheat

The effects of different factors on the embryogenesis and plant regeneration from mature embryos of Russian spring and winter genotypes were studied. Embryogenic callus induction was achieved on MS medium supplemented with different concentrations of 2,4-D (2,4-dichlorophenoxyacetic acid), 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) or Dicamba (3,6-dichloro-o-anisic acid). Although all auxins were able to induce callus from explants with high frequency (98–100%), Dicamba was more effective for the induction of embryogenic callus (21.8–38.3%). Maximum embryogenic callus formation and high number of regenerated plants were observed at 12 mg l⁻¹ of Dicamba. The time exposure to Dicamba (7, 14, 21 and 28 days) had a significant effect on efficiency of somatic embryogenesis. When contact of explants with callus induction medium was increased from 7 to 21 days the rate of somatic embryogenesis and number of regenerated plants per embryogenic callus gradually increased from 13.0 to 38.4% and 3.6 to 8.0%, respectively. Supplement of additional auxins (indoleacetic acid (IAA), indolebutyric acid (IBA), and naphthaleneacetic acid (NAA)) to callus induction medium with Dicamba had a positive effect on the rate of embryogenic callus formation, while the average number of regenerated shoots was not affected. The best rate of somatic embryogenesis was observed at the addition of 0.5 mg l⁻¹ IAA with Dicamba (61.0%). The optimum combination of Dicamba and IAA increased the efficiency of somatic embryogenesis and plant regeneration from seven spring and winter wheat genotypes, thought overall morphogenic capacity was still genotype dependent.     

The role of persistence and virulence factors in microecological changes in a humans

The patterns of persistence and virulence factors expression in the representatives of human microbial biocenosis depends on a complex of the environmental conditions: influence of microbes-symbionts, biotope peculiarities, properties of microorganisms located within eukaryotes. Interactions of symbionts in pairs "indigen-indigen" isolated from mucous membrane of tonsils in healthy persons, did not lead to changes in expression of pathogenic properties. Interinfluence in pairs "pathogen-indigen" and "indigen-indigen", isolated from patients with chronic tonsilitis were accompanied by an increase of anti-lysozyme, hemolytic and lecithovitellase activities. Migration of strains of non-enzymatized gram-negative bacteria (NEYNB) from nasal into tympanic cavity in experimental acute purulent otitis is connected with an earlier increase of their number in the nasal cavity and the expression of anti-lysozyme activity. In acute and chronic pyoderma, expression of ALA is more marked in bacteria from a perifocal damage in contrast to focal damage of normal skin. In conditions of interaction between erythrocytes and staphylococcal clones with different levels of expression of pathogenic factors, differences were observed in dynamics of hemolytic and anti-hemoglobin activities.     

c-fos Gene expression in the brain of rats with various exploratory and defensive behavior

Groups of active and passive Wistar rats were revealed in the "open field" and "hole exploration" tests. The pronounced c-fos gene expression was found in different brain structures of rats preliminary subjected to electrodermal stimulation in the "step down" test. Marked differences in c-fos gene expression were observed in brain structures of rats with the active and passive behavior in the "open field", "hole exploration", and "step down" tests. The most pronounced and intensive c-fos gene expression was noticed in the passive rats.