P518/Qrfp sequence polymorphisms in SAMP6 osteopenic mouse

Mice lacking GPR103A expression display osteopenia. Analysis of mouse quantitative trait loci literature associated with bone mineral density suggested GPR103A ligand P518/Qrfp (chromosome 2qB) as a candidate osteoporosis gene. Promoter and coding regions of mouse P518/Qrfp were sequenced from genomic DNA obtained from the osteoporosis-prone strain SAMP6 and control strains SAMR1, A/J, AKR/J, BALB/c, C3H/HeJ, C57BL/6J, and DBA/2J. Four single-nucleotide polymorphisms (SNPs) were identified in only SAMP6 genomic DNA, g.-1773 T-->C, g.110 A-->G (N37S), g.188 G-->A (R63K), and g.135 T-->C (H45H). The promoter SNP generated a novel neuron-restrictive silencing factor binding site, a repressor that decreases gene expression in nonneuronal tissues. TaqMan analysis demonstrated fivefold lower P518/Qrfp liver expression in SAMP6 versus SAMR1 or C57BL/6J control strains. Tissue distribution of human, mouse, and rat P518/Qrfp and its receptors showed expression in bone and spinal cord. A direct role for P518/Qrfp function in maintaining bone mineral density is suggested.     

Heterologous expression and isolation of influenza A virus nuclear export protein NEP

Influenza A virus nuclear export protein NEP (NS2, 14.4 kDa) plays a key role in various steps of the virus life cycle. Highly purified protein preparations are required for structural and functional studies. In this study, we designed a series of Escherichia coli plasmid constructs for highly efficient expression of the NEP gene under control of the constitutive trp promoter. An efficient method for extraction of NEP from inclusion bodies based on dodecyl sulfate treatment was developed. Preparations of purified NEP with either N-or C-terminal (His)₆-tag were obtained using Ni-NTA agarose affinity chromatography with yield of more than 20 mg per liter of culture. According to CD data, the secondary structure of the proteins matched that of natural NEP. A high propensity of NEP to aggregate over a wide range of conditions was observed.     

Seasonal and Long-Term Changes to Active-Layer Temperatures after Tall Shrubland Expansion and Succession in Arctic Tundra

Vegetation, active-layer soils, and snow cover regulate energy exchange between the atmosphere and permafrost. Therefore, interactions between changes to tundra vegetation and soil thermal regime will fundamentally affect permafrost in a warmer world. We recorded soil temperatures for approximately 1 year in a Siberian Low Arctic landscape with a known history of alder (Alnus) shrub expansion on disturbed microsites in patterned ground. We recorded near-surface soil temperatures and measured physical properties of soils and vegetation on sorted-circle microsites in four stages of shrubland development: (1) tundra lacking tall shrubs; (2) shrub colonization zones; (3) mature shrublands; and (4) paludified, long-established shrublands with thick soil organic layers. Summer soil temperatures declined with increasing shrub cover and soil organic thickness; shrub colonization suppressed cryoturbation, facilitating the development of continuous vegetation and a surface organic mat on circles. Compared to open tundra, mature shrubs cooled soils by up to 9 °C during summer, but warmed soils by greater than 10 °C in winter presumably because they developed highly insulative snowpacks. Paludified shrublands had the coldest summer active layers, but winter soil temperatures were much colder than mature shrublands and were similar to earlier stages. Our results indicate that although tall shrub establishment dramatically warms winter soils within decades, much of this warming is transient at paludification-prone sites because the buildup of wet peat favors cooling in winter and the stature and snow-trapping capacity of shrubs diminish over time. In the ecosystem we studied, shrub expansion has contrasting effects on active-layer temperatures both seasonally and over longer timescales due to successional processes.     

Lipid Peroxidation Rates,Hydrogen Peroxide Content,and Superoxide Dismutase Activity in Leaves of a Facultative CAM Plant Hylotelephium triphyllum (Haw.) Holub and a C3 Plant Plantago media L. under Natural Environmental Conditions

Russian Journal of Plant Physiology - Key indicators of pro-/antioxidant status were studied in leaves of Plantago media L. (C3 species) and Hylotelephium triphyllum (Haw.) Holub (facultative CAM...     

Respiration and nitrogen and carbohydrate contents in perennial rhizome-forming plants as related to realization of different adaptive strategies

Accumulation of biomass, the respiration rate, and the contents of total nitrogen and nonstructural carbohydrates were studied for 14 perennial long-rhizome-forming species differing in the type of adaptive strategy. Fast-growing species with well expressed competitive-ruderal properties (CR plants) were characterized by a higher productivity, a better nitrogen status, and more intense respiration than slowly growing stress-tolerant species (S plants). The proportion of rhizomes in the weight of the whole plant varied from 30 to 70% and was higher in S species. In CR species, the respiration rate measured in rhizomes at 20°C was equal on the average to 1 mg CO₂/(g dry wt h), which was threefold higher than in S species. In S species, a considerable amount of nitrogen (50%) was present in rhizomes, whereas in CR species, most part of nitrogen (70–80%) was localized in the aboveground organs. The correlation analysis revealed a direct dependence (r = 0.75) between the respiration rate and nitrogen content in leaves; in the rhizomes the correlation between these indices was low (r = 0.39). The content of carbohydrates in the leaves and sink organs, rhizomes, was determined by the type of plant ecological strategy and life duration of their photosynthesizing organs (summergreen, evergreen species). In general, the results obtained demonstrated a close relation between adaptive strategy, ecological confinement, the rhythm of seasonal development, and physiological properties of long-rhizome-forming plants.     

Multifold obtaining of reproductive products of Azov Shemaya Chalcalburnus chalcoides during spawning season

In the framework of studies on the development of biotechnical norms of artificial cultivation of anadromous Azov-Black Sea shemaya Chalcalburnus chalcoides spawning by stages, the possibility of increasing the efficiency of using spawners by twofold obtaining of reproductive products during one fishery season was revealed. The working fecundity increases by 90% at obtaining from females of the second batch of eggs as compared to that in the case of obtaining of only one batch. The level of heat build-up required for obtaining the second batch of eggs without hormonal stimulation was determined. For males of shemaya, the possibility of the repeated obtaining of reproductive products upon one day after hypophysation was shown.     

Microbial interactions in the mosquito gut determine Serratia colonization and blood-feeding propensity

How microbe–microbe interactions dictate microbial complexity in the mosquito gut is unclear. Previously we found that, Serratia, a gut symbiont that alters vector competence and is being considered for vector control, poorly colonized Aedes aegypti yet was abundant in Culex quinquefasciatus reared under identical conditions. To investigate the incompatibility between Serratia and Ae. aegypti, we characterized two distinct strains of Serratia marcescens from Cx. quinquefasciatus and examined their ability to infect Ae. aegypti. Both Serratia strains poorly infected Ae. aegypti, but when microbiome homeostasis was disrupted, the prevalence and titers of Serratia were similar to the infection in its native host. Examination of multiple genetically diverse Ae. aegypti lines found microbial interference to S. marcescens was commonplace, however, one line of Ae. aegypti was susceptible to infection. Microbiome analysis of resistant and susceptible lines indicated an inverse correlation between Enterobacteriaceae bacteria and Serratia, and experimental co-infections in a gnotobiotic system recapitulated the interference phenotype. Furthermore, we observed an effect on host behavior; Serratia exposure to Ae. aegypti disrupted their feeding behavior, and this phenotype was also reliant on interactions with their native microbiota. Our work highlights the complexity of host–microbe interactions and provides evidence that microbial interactions influence mosquito behavior.Subject terms: Symbiosis, Microbial ecology, Bacterial host response     

Comparative estimation of the “Membrane Reserve” of blood cells of reptiles and mammals

Based on the method of hypoosmotic loads, the value of membrane reserve and its use by blood cells of reptiles and mammals have been studied. It has been shown that lymphocytes of the both animal species have the highest reserve of plasmalemma, while frog heterophils—the lowest one. A significantly lower part of the membrane reserve participates in formation of phagosomes by mammalian neutrophils as compared with amphibian erythrocytes.     

The effect of destruction and stimulation of the lateral nucleus of the septum pellucidum on the structure and functions of the ovaries and the mechanism of such influences]

The experiments on the immature female rats were carried out to show the effects of damage or stimulation of the lateral septal nucleus (LSN) on the ovary function and its response to chorionic gonadotrophin. The damage of the LSN decreases the ovary weight, but enlarges mature ovarian follicles and increases the estrogen production. LSN lesions in hypophysectomized rats have no effect on the ovary and uterus weights as compared to hypophysectomized ones, but decrease the size of mature ovarian follicles against a background of hypophysectomy or LSN lesions. Damage of the LSN increases ovary and uterus sensitivity to the chorionic gonadotrophin injections. A conclusion is drawn on the existence of parahypophysial way to transfer the influence of LSN on the rat ovaries. The possible mechanisms of LSN influence on the reproduction system of female rats is under discussion.