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.     

Reversible Large-Body Formation from Nuclear Bodies upon Amino Acid(s) Starvation in T24 Cells

AP435 dot, a nuclear dot-like structure that is recognized by a monoclonal antibody AP435 MAb and that seems to correlate with perinuclear intermediate filaments, was identified as a nuclear body by double immunofluorescent staining with AP435 MAb and the nuclear-body-specific antibody αSp100 or mAb 5E10. In T24 cells, nuclear bodies usually appear as small entities with an apparent diameter ranging from 0.2 to 0.7 μm, and several to 20 or more of them are present per nucleus. After long culture without a change in the medium, however, nuclear bodies disappeared while one or more large doughnut-shaped bodies appeared, which had apparent outer diameters of 0.7–1.8 μm. When the medium was changed or medium components were added, large bodies disappeared and many nuclear bodies of normal size reappeared within several hours. Large-body formation was not related to the arrest of DNA synthesis, as revealed by double labeling with AP435 MAb and anti-cyclin antibody. Among the medium components, only an amino acid mixture induced the change from large bodies to nuclear bodies. Large-body formation was also observed in long-cultured HeLa cells. These results suggest that nuclear bodies reversibly aggregate or reorganized to form large bodies upon amino acid(s) starvation.     

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.     

Transgenic mouse lines with ectopic expression of {alpha}-1, 3-galactosyltransferase: production and characteristics

The cDNA of murine     

Spermiogenesis in the Nile tilapia Oreochromis niloticus with notes on a unique pattern of nuclear chromatin condensation

Spermiogenesis in the Nile tilapia, Oreochromis niloticus, was observed ultrastructurally. The process of spermatid differentiation can be divided into six distinct stages based mainly on changes in the nucleus of spermatids. During the latter half of the process, nuclear chromatin condenses progressively to form many dense globules, which ultimately adhere tightly to pack the head of mature spermatozoa. During chromatin condensation the nucleus diminishes in size, and part of the nuclear envelope and nucleoplasm forms a vesicular structure that is finally discarded from the cells together with an associated thin layer of cytoplasm. The spermatozoon comprises a roundish head, a relatively small midpiece, and a relatively short flagellum consisting of the usual 9+2 axoneme. No acrosomal structure is developed during spermiogenesis.