Mesorhizobium sp. J8 can establish symbiosis with Glycyrrhiza uralensis,increasing glycyrrhizin production

Licorice (Glycyrrhiza uralensis) is a medicinal plant that contains glycyrrhizin (GL), which has various pharmacological activities. Because licorice is a legume, it can establish a symbiotic relationship with nitrogen-fixing rhizobial bacteria. However, the effect of this symbiosis on GL production is unknown. Rhizobia were isolated from root nodules of Glycyrrhiza glabra, and a rhizobium that can form root nodules in G. uralensis was selected. Whole-genome analysis revealed a single circular chromosome of 6.7 Mbp. This rhizobium was classified as Mesorhizobium by phylogenetic analysis and was designated Mesorhizobium sp. J8. When G. uralensis plants grown from cuttings were inoculated with J8, root nodules formed. Shoot biomass and SPAD values of inoculated plants were significantly higher than those of uninoculated controls, and the GL content of the roots was 3.2 times that of controls. Because uninoculated plants from cuttings showed slight nodule formation, we grew plants from seeds in plant boxes filled with sterilized vermiculite, inoculated half of the seedlings with J8, and grew them with or without 100 µM KNO₃. The SPAD values of inoculated plants were significantly higher than those of uninoculated plants. Furthermore, the expression level of the CYP88D6 gene, which is a marker of GL synthesis, was 2.5 times higher than in inoculated plants. These results indicate that rhizobial symbiosis promotes both biomass and GL production in G. uralensis.     

A Naturally Occurring Canine Model of Autosomal Recessive Congenital Stationary Night Blindness

Congenital stationary night blindness (CSNB) is a non-progressive, clinically and genetically heterogeneous disease of impaired night vision. We report a naturally-occurring, stationary, autosomal recessive phenotype in beagle dogs with normal daylight vision but absent night vision. Affected dogs had normal retinas on clinical examination, but showed no detectable rod responses. They had “negative-type” mixed rod and cone responses in full-field ERGs. Their photopic long-flash ERGs had normal OFF-responses associated with severely reduced ON-responses. The phenotype is similar to the Schubert-Bornschein form of complete CSNB in humans. Homozygosity mapping ruled out most known CSNB candidates as well as CACNA2D4 and GNB3. Three remaining genes were excluded based on sequencing the open reading frame and intron-exon boundaries (RHO, NYX), causal to a different form of CSNB (RHO) or X-chromosome (NYX, CACNA1F) location. Among the genes expressed in the photoreceptors and their synaptic terminals, and mGluR6 cascade and modulators, reduced expression of GNAT1, CACNA2D4 and NYX was observed by qRT-PCR in both carrier (n = 2) and affected (n = 2) retinas whereas CACNA1F was down-regulated only in the affecteds. Retinal morphology revealed normal cellular layers and structure, and electron microscopy showed normal rod spherules and synaptic ribbons. No difference from normal was observed by immunohistochemistry (IHC) for antibodies labeling rods, cones and their presynaptic terminals. None of the retinas showed any sign of stress. Selected proteins of mGluR6 cascade and its modulators were examined by IHC and showed that PKCα weakly labeled the rod bipolar somata in the affected, but intensely labeled axonal terminals that appeared thickened and irregular. Dendritic terminals of ON-bipolar cells showed increased Goα labeling. Both PKCα and Goα labeled the more prominent bipolar dendrites that extended into the OPL in affected but not normal retinas. Interestingly, RGS11 showed no labeling in the affected retina. Our results indicate involvement of a yet unknown gene in this canine model of complete CSNB.     

Restoration of transforming growth factor-beta type II receptor reduces tumorigenicity in the human adrenocortical carcinoma SW-13 cell line.

Transforming growth factor-beta (TGF-beta) is a potent growth suppressor. Acquisition of TGF-beta resistance has been reported in many tumors, and has been associated with reduced TGF-beta receptor expression. In this study, we examined TGF-beta 1, TGF-beta type I receptor (TbetaRI) and TGF-beta type II receptor (TbetaRII) expression in SW-13 adrenocortical carcinoma cells by Northern and Western blot analysis. SW-13 cells did not express TbetaRII mRNA or protein. We have investigated the role of TbetaRII in modulating tumorigenic potential using stably transfected SW-13 cells with TbetaRII expression plasmid. TbetaRII-positive SW-13 cell growth was inhibited by exogenous human TGF-beta1 (hTGF-beta1) in a dose-dependent manner. In contrast, SW-13 cells and control clones transfected with empty vector remained hTGF-beta1-insensitive. Xenograft examination in athymic nude mice demonstrated that TbetaRII-positive SW-13 cells reduced tumor-forming activity. Reconstructing the TbetaRII can lead to reversion of the malignant phenotype of TbetaRII-negative human adrenocortical carcinoma, which contains SW-13 cells. Reduced TbetaRII expression may play a critical role in determining the malignant phenotype of human adrenocortical carcinoma.     

A possible discrepancy between the exposed and the whole population depending on range-size and trap-spacing in vole populations

Population Ecology - From a field study for the vole population (Clethrionomys rufocanus) in Hokkaido in the late summer of 1965, it has been proved that the range length may decrease from 25 to 18...     

New highly active taxoids from 9 beta-dihydrobaccatin-9,10-acetals. Part 5

To improve the metabolic stability of 3, which exhibited both in vitro antitumor activity and in vivo efficacy by both iv and po administration, we designed and synthesized new taxane analogues. Most of the synthetic compounds maintained excellent antitumor activity and were scarcely metabolized by human liver microsomes. And some compounds exhibited potent antitumor effects against B16 melanoma BL6 in vivo by both iv and po administration similarly to 3.     

Molecular Characterization of a Deep-Sea Methanotrophic Mussel Symbiont that Carries a RuBisCO Gene

In our previous investigation on the genes of 1,5-ribulose bisphosphate carboxylase/oxygenase (RuBisCO; EC 4.1.1.39) in deep-sea chemoautotrophic and methanotrophic endosymbioses, the gene encoding the large subunit of RuBisCO form I (cbbL) had been detected in the gill of a mussel belonging to the genus Bathymodiolus from a western Pacific back-arc hydrothermal vent. This study further examined the symbiont source of the RuBisCO cbbL gene along with the genes of 16S ribosomal RNA (16S rDNA) and particulate methane monooxygenase (EC 1.14.13.25; pmoA) and probed for the presence of the ATP sulfurylase gene (EC 2.7.7.4; sopT). The 16S rDNA sequence analysis indicated that the mussel harbors a monospecific methanotrophic Gammaproteobacterium. This was confirmed by amplification and sequencing of the methanotrophic pmoA, while thiotrophic sopT was not amplified from the same symbiotic genome DNA. Fluorescence in situ hybridization demonstrated simultaneous occurrence of the symbiont-specific 16S rDNA, cbbL and pmoA, but not sopT, in the mussel gill. This is the first molecular and visual evidence for a methanotrophic bacterial endosymbiont that bears the RuBisCO cbbL gene relevant to autotrophic CO₂ fixation.     

Nitric oxide signaling in yeast

As a cellular signaling molecule, nitric oxide (NO) is widely conserved from microorganisms, such as bacteria, yeasts, and fungi, to higher eukaryotes including plants and mammals. NO is mainly produced by NO synthase (NOS) or nitrite reductase (NIR) activity. There are several NO detoxification systems, including NO dioxygenase (NOD) and S-nitrosoglutathione reductase (GSNOR). NO homeostasis based on the balance between NO synthesis and degradation is important for the regulation of its physiological functions because an excess level of NO causes nitrosative stress due to the high reactivity of NO and NO-derived compounds. In yeast, NO may be involved in stress responses, but NO and its signaling have been poorly understood due to the lack of mammalian NOS orthologs in the genome. Even though the activities of NOS and NIR have been observed in yeast cells, the gene encoding NOS and the NO production mechanism catalyzed by NIR remain unclear. On the other hand, yeast cells employ NOD and GSNOR to maintain an intracellular redox balance following endogenous NO production, exogenous NO treatment, or environmental stresses. This article reviews NO metabolism (synthesis, degradation) and its regulation in yeast. The physiological roles of NO in yeast, including the oxidative stress response, are also discussed here. Such investigations into NO signaling are essential for understanding the NO-dependent genetic and physiological modulations. In addition to being responsible for the pathology and pharmacology of various degenerative diseases, NO signaling may be a potential target for the construction and engineering of industrial yeast strains.     

Cyclooxygenase-2/prostaglandin E2 accelerates the healing of gastric ulcers via EP4 receptors

We examined the involvement of cyclooxygenase (COX)-1 as well as COX-2 in the healing of gastric ulcers and investigated which prostaglandin (PG) EP receptor subtype is responsible for the healing-promoting action of PGE2. Male SD rats and C57BL/6 mice, including wild-type, COX-1(-/-), and COX-2(-/-), were used. Gastric ulcers were produced by thermocauterization under ether anesthesia. Gastric ulcer healing was significantly delayed in both rats and mice by indomethacin and rofecoxib but not SC-560 given for 14 days after ulceration. The impaired healing was also observed in COX-2(-/-) but not COX-1(-/-) mice. Mucosal PGE2 content increased after ulceration, and this response was significantly suppressed by indomethacin and rofecoxib but not SC-560. The delayed healing in mice caused by indomethacin was significantly reversed by the coadministration of 11-deoxy-PGE1 (EP3/EP4 agonist) but not other prostanoids, including the EP1, EP2, and EP3 agonists. By contrast, CJ-42794 (selective EP(4) antagonist) significantly delayed the ulcer healing in rats and mice. VEGF expression and angiogenesis were both upregulated in the ulcerated mucosa, and these responses were suppressed by indomethacin, rofocoxib, and CJ-42794. The expression of VEGF in primary rat gastric fibroblasts was increased by PGE2 or AE1-329 (EP4 agonist), and these responses were both attenuated by coadministration of CJ-42794. These results confirmed the importance of COX-2/PGE2 in the healing mechanism of gastric ulcers and further suggested that the healing-promoting action of PGE2 is mediated by the activation of EP4 receptors and is associated with VEGF expression.     

Biological traits of naturally induced hybrid individuals of two gizzard shads, <Emphasis Type="Italic">Nematalosa come</Emphasis> and <Emphasis Type="Italic">N. japonica</Emphasis>, in coastal waters around Okinawa Island,Ryukyu Archipelago,southwestern Japan

The age, growth, reproductive condition, and occurrence of natural hybrids of two Nematalosa species around Okinawa Island were examined using 128 specimens obtained from April 2003 to June 2004. Standard length (SL) reached approximately 150–210 mm within the first 2 years, and then remained stagnant. The maximum age for both sexes was ca. 5 years old. Maturity sizes and ages were estimated to be at least 173.2 mm SL and 2 years old for females and 192.6 mm SL and 3 years old for males. Spawnable individuals were mainly observed from January to March based on histological observations of gonads. Natural hybrids appeared at all sampling sites except for the Haneji Inlet and were dominant at Makiminato (in south-central Okinawa Island). Their incidence was also quite high (66.9%) in the Makiminato population, when compared with records for other marine fishes around Japan. In Okinawa Island, these shallow areas are rapidly decreasing in size because of recent reclamation and land exploitation. Hybrid production may be caused by not only the reproductive biology and sympatric distributions of the parent species but also recent environmental changes.     

Establishment of a sandwich ELISA system to detect diapause hormone, and developmental profile of hormone levels in egg and subesophageal ganglion of the silkworm, Bombyx mori

In the silkworm Bombyx mori, diapause hormone (DH) is produced in the female subesophageal ganglion (SG) and induces embryonic diapause by targeting developing ovaries. DH is processed from a precursor protein consisting of DH, pheromone biosynthesis activating neuropeptide (PBAN) and three other neuropeptides (SGNPs). Because these five neuropeptides share a common sequence, FXPRLamide, at the C-terminus, a direct and specific assay for DH itself is required in order to understand the profile of concentration changes. In this study, we produced a mouse monoclonal antibody (anti-DH[N] mAb) against the N-terminal region of DH and developed a sandwich enzyme-linked immunosorbent assay using the anti-DH[N] mAb and a rabbit polyclonal antibody against the C-terminus of DH. This procedure enabled us to specifically quantify the DH molecule at femtomolar levels (equivalent to 1/10 of SG). We then plotted DH levels in eggs and SGs during embryonic and post-embryonic development. DH was present in late-stage embryos that had been destined for the production of both diapause and nondiapause eggs. DH levels in SG gradually increased in both types during larval development and peaked at the early pupal stage. At the middle pupal stage, DH levels in SG and SG-brain complex decreased markedly in the diapause-egg producing type, thus indicating active release of DH into the hemolymph. From 5th instar larva to adult, no sexual differences in DH levels were observed in SGs or SG-brain complexes from diapause and nondiapause egg-producing types.