Development of the IRGA enclosed-chamber system for soil CO<Subscript>2</Subscript> efflux measurement and its application to a spatial variation measurement

A new system was developed for measuring soil CO₂ efflux. The chamber in this system contains a small infrared CO₂ gas analyzer. This system does not need air tubes or pumps for circulating air, so it is expected to offer the advantages of mobility and durability. This system was verified by a comparison with measurements made by using a closed-dynamic-chamber (CDC) system. The spatial variation in the soil CO₂ efflux in a broadleaved deciduous forest was measured using the new system. The soil CO₂ efflux at sampling locations 50–70cm apart varied within a range of 60%–150%. This variation was smaller than the variation due to differences in soil characteristic reflected in different moisture conditions, etc.     

RAPDs和RFLPs分析甘蓝型杂交油菜亲本的遗传多样性

利用RAPD和RFLP分子标记技术对甘蓝型杂交油菜亲本遗传多样性的分析结果表明:(1)20个亲本间具有丰富的遗传多样性,40个引物扩增出277条多态性带,其中21条带为10个亲本所特有,12个探针得到了117条多态性杂交带,其中7条带为5个亲本所特有;(2)不育系与恢复系之间的遗传差异大于不育系内和恢复系内的遗传差异;(3)依RAPDs与RFLPs估     

Molecular analysis and physicochemical properties of electrophoretic variants of wild soybean Glycine soja storage proteins

Cultivated soybeans (Glycine max) are derived from wild soybeans (Glycine soja) and can be crossed with them to produce fertile offspring. The latter exhibit greater genetic variation than the former, suggesting a possibility that wild soybeans contain storage proteins with properties different from and better than those of cultivated soybeans. To identify a wild soybean suitable for breeding a new soybean cultivar, we analyzed seed proteins from 390 lines of wild soybeans by electrophoresis. We found some lines containing electrophoretic variants of glycinin and beta-conglycinin subunits: one line containing a small alpha' subunit of beta-conglycinin and two and five lines containing small A3 and large A4 polypeptides of glycinin, respectively. Beta-Conglycinin and glycinin containing such variant subunits exhibited solubility and emulsifying ability similar to those of the predominant types of wild and cultivated soybeans. Glycinins containing small A3 and large A4 gave a shoulder derived from the start of denaturation at a temperature 4 degrees C lower than that of glycinin from the predominant types of wild and cultivated soybeans, although their thermal denaturation midpoint temperatures were very similar to each other. Cloning and sequencing of the predominant and variant subunit cDNAs revealed that the small alpha' and the small A3 lacked 24 amino acid residues in the extension region and four amino acid residues in the hypervariable region, respectively, and that the large A4 did not have an insert corresponding to the difference in the electrophoretic mobility but Arg279 and Gln305 were replaced by glutamine and histidine, respectively, in the hypervariable region. These suggest that small differences even in the hypervariable region can affect the thermal stability, as well as the electrophoretic mobilities, of the proteins.     

Protective activity of green tea against free radical- and glucose-mediated protein damage

Protein oxidation and glycation are posttranslational modifications that are implicated in the pathological development of many age-related disease processes. This study investigated the effects of green tea extract, and a green tea tannin mixture and its components, on protein damage induced by 2,2'-azobis(2-amidinopropane) dihydrochloride (a free radical generator) and glucose in in vitro assay systems. We found that green tea extract can effectively protect against protein damage, and showed that its action is mainly due to tannin. In addition, it was shown that the chemical structures of tannin components are also involved in this activity, suggesting that the presence of the gallate group at the 3 position plays the most important role in the protective activity against protein oxidation and glycation, and that there is also a contribution by the hydroxyl group at the 5' position in the B ring and the sterical structure. These findings demonstrate the mechanisms of the usefulness of green tea in protein oxidation- and glycation-associated diseases.     

Babesia microti-like parasites detected in Eurasian red squirrels (Sciurus vulgaris orientis) in Hokkaido, Japan

Six Eurasian red squirrels (Sciurus vulgaris orientis), victims of road traffic found during 2002 and 2004 near the Noppro Forest Park in Ebetsu, Hokkaido, Japan, were examined for the presence of Babesia parasites. Three of the six squirrels exhibited positive signals by nested PCRs targeting both the 18S rRNA and beta-tubulin genes. Three squirrels proved to be infected with a B. microti-like parasite as evidenced by sequencing the amplified DNAs and by the morphology of the intraerythrocytic parasites. Genotypically, however, the parasite appeared to be of a new type, as it was clearly distinguishable from any of the known types that have previously been reported in various wild animals. This is the first report showing molecular evidence for the presence of B. microti-like parasites in Sciuridae.     

Characterization and crystallography of recombinant 7S globulins of Adzuki bean and structure-function relationships with 7S globulins of various crops

The recombinant proteins Adzuki 7S1, Adzuki 7S2, and Adzuki 7S3 were prepared through the Escherichia coli expression systems of three kinds of adzuki bean cDNAs. The recombinant proteins exhibited intrinsic thermal stabilities, surface hydrophobicities, and solubilities, although the homology of their amino acid sequences ranged from 95-98%. To understand why these individual proteins exhibited different properties, their three-dimensional structures were elucidated. The three proteins were successfully crystallized, and the three-dimensional structures of Adzuki 7S1 and Adzuki 7S3 were determined. The properties and structures of these two proteins were comprehensively compared with those of recombinant 7S globulins (soybean beta-conglycinins beta and alpha'c and mungbean 8Salpha) reported previously. It was likely that cavity sizes, hydrogen bonds, salt bridges, hydrophobic interactions, and lengths of loops determine the thermal stabilities of 7S globulins, and results indicated that cavity sizes strongly contribute to such stability. Surface hydrophobicity was also found to be determined not only by distributions of hydrophobic residues on the molecular surface. Furthermore, solubility at neutral and weak alkaline pH values at mu = 0.08 was found to be dominantly influenced by the electrostatic surface potentials.     

Association between preoperative characteristics and risk of anaesthesia-related death in dogs in small-animal referral hospitals in Japan

Objective

To explore the major risk factors linking preoperative characteristics and anaesthesia-related death in dogs in referral hospitals in Japan.

Isolation of exfoliative toxin from Staphylococcus intermedius and its local toxicity in dogs

A rounding effect was demonstrated in cultured cells inoculated with the culture filtrates (CFs) of 60 strains of Staphylococcus intermedius derived from dogs affected with pyoderma. Exfoliative toxin (ET)-like toxin (ETLT) was isolated from the CF of S. intermedius strain D-52, which exhibited strong rounding activity and then was purified by gel filtration on a Sephadex G-75 column, and by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The ETLT caused exfoliation in 1-day-old chickens, suckling Syrian hamsters, and dogs, but not in suckling mice. The ETLT was serologically different from exfoliative toxin A (ETA), exfoliative toxin B (ETB), exfoliative toxin C (ETC), S. hyicus exfoliative toxin A (SHETA), and SHETB, as shown by Western blot analysis. The molecular weight of the ETLT was estimated at 30 kDa by SDS-PAGE. In the present study, we propose the ETLT was a novel type of ET, S. intermedius exfoliative toxin (SIET).