Stress resistance and C1 metabolism involved in plant colonization of a methanotroph Methylosinus sp. B4S

Methanotrophs are widespread and have been isolated from various environments including the phyllosphere. In this study, we characterized the plant colonization by Methylosinus sp. B4S, an α-proteobacterial methanotroph isolated from plant leaf. The gfp-tagged Methylosinus sp. B4S cells were observed to colonize Arabidopsis leaf surfaces by forming aggregates. We cloned and sequenced the general stress response genes, phyR, nepR and ecfG, from Methylosinus sp. B4S. In vitro analysis showed that the phyR expression level was increased after heat shock challenge, and phyR was shown to be involved in resistance to heat shock and UV light. In the phyllospheric condition, the gene expression level of phyR as well as mmoX and mxaF was found to be relatively high, compared with methane-grown liquid cultures. The phyR-deletion strain as well as the wild-type strain inoculated on Arabidopsis leaves proliferated at the initial phase and then gradually decreased during plant colonization. These results have shed light firstly on the importance of general stress resistance and C1 metabolism in methanotroph living in the phyllosphere.     

Androgen receptor in human placental villi

In studies with a synthetic androgen, R 1881, an androgen-binding component was found in the cytosol of human placental villi. Kinetic analysis indicated that the Kd value of this component was 1.4 nM at 0-4 degrees C and that binding of R 1881 amounted to 277 +/- 73 fmol/mg protein. glycerol density gradient ultracentrifugation showed a peak of binding activity in the 8S region in a medium of low ionic strength, but in the 4.5S region in a medium containing 9.5 M KCl. The R 1881-binding component was inactivated by mild heat- or trypsin-treatment, but not by treatment with DNase or RNase. Most of the R 1881-binding activity was sedimented at 20 to 40% saturation of ammonium sulfate. These findings indicate that the R 1881-binding component in human placental cytosol is quite similar in its characteristics to androgen receptors, which are present in various androgen-responsive organs. Testosterone was a more potent competitor of R 1881-binding than DHT or cyproterone acetate. Scatchard plots indicated that the binding site of testosterone was identical with that of R 1881. These findings suggest that the androgen receptor in placental cytosol is specific for testosterone. The Kd value for testosterone was calculated to be 3.2 nM.     

Interaction between Staphylococcus Agr virulence and neutrophils regulates pathogen expansion in the skin

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Geographical continuity and discontinuity in the meristic characteristics of ayus of the southern subspecies Plecoglossus altivelis ryukyuensis

Ichthyological Research - Two subspecies of ayu, Plecoglossus altivelis altivelis (nominotypical subspecies) and P. a. ryukyuensis (Ryukyu-ayu), differ morphologically, behaviorally, and...     

Pathways to chronic inflammation in rheumatoid synovitis

Postcapillary venules resembling the high endothelial venules (HEVs) of lymphoid tissues have often been observed at sites of chronic inflammation. We have therefore postulated that such venules may be an important site of lymphocyte migration into rheumatoid synovial membrane and that inflammatory cell products may act on endothelial cells (ECs) to increase lymphocyte emigration. Electron microscopic examination of rheumatoid synovial membranes showed that a strong correlation existed between the proportion of lymphocytes in perivascular tissue and the height/base ratio of the ECs in those areas. In addition, binding experiments showed that peripheral blood mononuclear cells preferentially bound to ECs in sections of rheumatoid synovial membrane that had the morphological appearance of HEVs. In vitro binding experiments, in which lymphocyte adhesion to human umbilical vein EC monolayers was measured, showed that adhesion was enhanced by preincubation of the ECs with interferon-gamma or interleukin 1 (IL 1). The central role of IL 1 in increasing lymphocyte migration into the rheumatoid synovial membrane was also supported by the findings that IL 1 is chemotactic for lymphocytes, ECs can secrete IL 1, and IL 1 activity is readily detectable in synovial fluids of rheumatoid arthritis patients.     

LHRH increases plasma 7B2 concentration in normal human subjects

We studied the response of plasma 7B2 to LHRH and ovine corticotropin releasing hormone (o-CRH) in healthy young subjects. The plasma 7B2 concentration significantly increased from 78.3 +/- 7.5 (mean +/- SEM) to 102.0 +/- 6.0 ng/L (142.7 +/- 12.7% of the basal value; P less than 0.01) following iv administration of LHRH in seven young subjects. On the other hand, no increase in plasma 7B2 was found after iv administration of o-CRH in six young subjects. These results, together with our previous report of no increase in plasma 7B2 after administration of TRH and GHRH in young subjects, suggest that pituitary 7B2 may be present in gonadotrophs and be released only by LHRH in physiological conditions.     

Effect of saline water on early success of amphidromous fish

Organisms that migrate between rivers and the sea inevitably pass through estuarine habitats. Despite the potential importance of salinity and temperature fluctuations for metabolic adaptation, little is known about the impact of environmental changes in estuaries on the survival of residents. Ayu (Plecoglossus altivelis) is a migratory fish that inhabits estuarine brackish water in its early life stages. The recent decline in the abundance of populations ascending into rivers is of concern for local biodiversity. The present study aims to elucidate the ecological processes that determine the early success of Ayu larvae under variable environmental conditions. The effects of salinity and water temperature on the endogenous growth of newly hatched larvae from the same brood were examined experimentally based on morphological and metabolic characteristics. High salinity and high water temperature together appeared to require more energy for larval osmoregulation, resulting in the acceleration of yolk depletion and reduced growth of the notochord. Increasing the osmoregulative cost during the yolk-sac stage resulted in the faster induction of a state of starvation. Seawater is considered to have an adverse effect on the survival of newly hatched larvae, as it lowers the efficiency of foraging and predator avoidance due to an energetic tradeoff. More attention should be paid to the significance of estuarine environments involving brackish waters to ensure the early survival of amphidromous fish such as Ayu.     

Methanol bioeconomy: promotion of rice crop yield in paddy fields with microbial cells prepared from natural gas-derived C1 compound

Methylotrophs, which can utilize methanol as a sole carbon source, are promising microorganisms to be exploited in a methanol-based bioeconomy, in which a variety of useful compounds are biotechnologically produced from natural gas-derived methanol. Pink-pigmented facultative methylotrophs (PPFMs) are common plant phyllospheric bacteria and are known to enhance seedling growth and total biomass of various plants. However, improvement of crop yield by inoculation of PPFMs at the field level has not been well investigated. We herein describe improvement of crop yield of several rice cultivars by foliar spraying of PPFMs. After selection of PPFM strains and rice cultivars by the in vitro seedling growth test, we further conducted paddy field experiments. The crop yield of the sake-brewing rice Oryza sativa cultivar Hakutsurunishiki was reproducibly improved in a commercial paddy field for over a 5-year period. A one-time foliar spray of PPFM cells (living or killed) or a cell wall polysaccharide fraction, after the heading date, acted in the phyllosphere and effectively improved crop yield. Our results show that the established process with PPFMs is feasible for improvement of food production in the methanol bioeconomy.