Characterization of Thiamin‐Binding Protein from Wheat Germ

A thiamin‐binding protein was isolated from wheat germ (Triticum aestivum). Its molecular mass was estimated as 120,000 Da consisting of two 56,000‐subunits. The protein contained a large amount of glutamine or glutamic acid (15.4 mol%), arginine (12.5 mol%), and glycine (12.0 mol%). The levels of tyrosine, methionine, tryptophan, and cysteine in the protein were low. Optimum pH for its thiamin‐binding activity was pH 8.0. It bound free thiamin specifically, not thiamin phosphates. The apparent dissociation and maximum bound values for the thiamin‐binding were 2.52 μM and 9.34 nmol/mg of protein, respectively. Properties of the thiamin‐binding protein from wheat germ were similar to those of the thiamin‐binding protein from rice seeds, but not from buckwheat, sesame, or sunflower seeds.     

Shiga toxin 2eB-transgenic lettuce vaccine: N-glycosylation is important for protecting against porcine edema disease

Porcine edema disease (ED) is a life-threatening toxemia caused by enteric infection with Shiga toxin 2e (Stx2e)-producing Escherichia coli (STEC) in weaned piglets. We previously reported that the stx2eB-transgenic lettuce 2BH strain shows potential for use as an oral vaccine candidate against ED. However, the 2BH strain expressed a hemagglutinin (HA)-tag together with Stx2eB and contained non-canonical N-glycosylation. Therefore, we developed two Stx2eB-lettuce strains, the 3 (G+) strain in which the HA-tag was removed from 2BH, and the 3 (G-) lettuce strain, in which the 73rd Asn was replaced with Ser to prevent non-canonical N-glycosylation of Stx2eB from the 3 (G+) strain. We examined the protective effect of these newly developed two strains compared with the previous 2BH strain against ED using a colostrum-deprived piglet STEC infection model. We found that the N-glycosylated 2BH and 3 (G+) strains relieved the pathogenic symptoms of ED in STEC-challenged piglets, whereas the non-glycosylated 3 (G-) strain did not. N-Glycosylation of the Stx2eB product in lettuce may be involved in the immune response in piglets.     

Effect of prostaglandin F2α administration on uterine polymorphonuclear neutrophil counts in Japanese heavy draft horses

The objective of this study was to examine the effect of prostaglandin F2_α (dinoprost) and oxytocin administration on uterine polymorphonuclear neutrophil counts in the Japanese heavy draft mare. To compare polymorphonuclear neutrophil (PMN) counts in the endometrium, a total of 162 samples were collected from 54 estruses of 47 mares (before ovulation, day 0, and day 2) using a double-guarded cytology brush. Dinoprost (PG; 5 mg) was administered intramuscularly (i.m.) only once, on day 0, whereas oxytocin (OT; 20 U i.m.) was administered three times at 12-hr intervals starting on day 0. The plasma progesterone concentrations from days 0 to 14 were not different between the non-treatment (CON), PG treatment, and OT treatment groups. The PMN counts increased in all the groups from before administration to day 0 (CON, 0.90 to 3.55; PG, 1.20 to 8.45; and OT, 0.70 to 1.70; P=0.0014, 0.0046, and 0.0073, respectively). There was a significant decrease in PMNs from day 0 to day 2 only in the PG group (P=0.0073). The pregnancy rate was not different among the CON (12/18), PG (14/18), and OT (10/18) groups. The results of this study indicate that dinoprost can reduce uterine polymorphonuclear neutrophil counts.     

Dynamics of physicochemical properties and occurrence of fungal fruit bodies during decomposition of coarse woody debris of Fagus crenata

The pattern of changes in the physicochemical properties of wood, and its relationship with fungal succession during decomposition of coarse woody debris (CWD) of beech (Fagus crenata Blume) were investigated. In total, 47 snags and 66 logs were assigned to a system of five decay classes, and were used for analysis of the decomposition process. The decomposition process consists of two phases characterized by their dominant organic chemical constituents. In the first phase (decay class 1–3), acid-unhydrolyzable residue (AUR) and holocellulose decreased simultaneously. In the second phase (decay class 3–5), holocellulose decayed selectively. Fruiting bodies of ten fungal taxa occurred frequently on decomposing logs and/or snags. These fungi were divided into early and late colonizers according to their occurrence during CWD decomposition. The relationship between fungal community composition and the physicochemical properties of CWD was analyzed by canonical correspondence analysis (CCA). According to the Monte Carlo permutation test, decay class, water content, and type of CWD (log or snag) significantly affected the fungal community structure. Our results suggested that white-rot basidiomycetes, especially Omphalotus guepiniformis, play a central role in the simultaneous decomposition of AUR and holocellulose in the first phase of decomposition. On the other hand, fungal taxa occurring in the second phase of decomposition may not be responsible for the decomposition of holocellulose. Three possible mechanisms of holocellulose decomposition and AUR accumulation in the second phase of decomposition are proposed and discussed. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Effect of Frankia inoculation on the growth of Alnus sieboldiana on unsterilized soil

The effect of inoculation with Frankia, a N-fixing actinomycete, on the growth of Alnus sieboldiana seedlings was studied on unsterilized soil from a nursery and an alder stand (forest of Alnus firma). The seedlings of A. sieboldiana were inoculated with Frankia before or after a 2-month culture on sterilized vermiculite, during which they nodulated, and transplanted to unsterilized soil from the nursery and the alder stand. The control seedlings were also cultured on sterilized vermiculite for about 2 months and transplanted to unsterilized soil without Frankia inoculation. The seedling growth, nodulation and N-fixing activity were measured 3, 10 and 16 weeks after the transplantation. Growth and nodule biomass of the seedlings inoculated with Frankia and those grown on the alder soil were better than those without inoculation with Frankia and grown on the nursery soil, respectively. The seedlings inoculated before spontaneous nodulation grew better than those inoculated at the transplantation. Nitrogen-fixing activity measured by acetylene reduction assay at 16 weeks after the transplantation was higher in the seedlings grown on the soil from the nursery than on the soil from the alder stand.     

Fine Mapping of HWC2, a Complementary Hybrid Weakness Gene, and Haplotype Analysis Around the Locus in Rice

Hybrid weakness is a reproductive barrier. In rice, the hybrid weakness caused by two complementary genes––HWC1 and HWC2––has been surveyed extensively. However, their gene products and the molecular mechanism that causes hybrid weakness have remained unknown. We first performed fine mapping of HWC2, narrowing down the area of interest to 19 kb. We thereby identified five candidate genes. Second, we performed haplotype analysis around the HWC2 locus of 33 cultivars. With 15 DNA markers examined, all the 13 Hwc2-1 carriers share the same haplotype for consecutive 14 DNA markers. As for hwc2-2 carriers, five out of 20 have the haplotypes relatively similar to those of Hwc2-1 carriers. However, the other haplotypes differ remarkably from them. These results are useful to identify the HWC2 gene and to study rice varietal differentiation.     

Vortex flow produced by schooling behavior of arabesque greenling <Emphasis Type="Italic">Pleurogrammus azonus</Emphasis>

Arabesque greenling Pleurogrammus azonus form schools of 30,000–60,000 individuals to feed on mesozooplankton near the sea surface. The fish need to be close to the surface where mesozooplankton production occurs, but the food is not sufficiently dense there for the fish to grow optimally while avoiding predation by sea birds. Arabesque greenling use a unique method to optimize their feeding conditions while avoiding staying on the sea surface. When the school swims upward, water is pushed downward. Upward swimming of a school of 30,000 individuals generates a downward stream of about 0.8–1.1 m/s, resulting in a convergent flow near the surface. This convergence concentrates the mesozooplankton on the sea surface and transports them into deeper layers with a strong vortex about 3.0 m in diameter and 10–20 m long. Thus, schooling of this fish induces vortex flows that provide a rich feeding environment.     

Role of taurine deficiency in inducing green liver symptom and effect of dietary taurine supplementation in improving growth in juvenile red sea bream <Emphasis Type="Italic">Pagrus major</Emphasis> fed non-fishmeal diets based on soy protein concentrate

This study was conducted to investigate the mechanism of green liver symptom induction and the effect of dietary taurine supplementation on growth performance in juvenile red sea bream fed non-fishmeal diets based on soy protein concentrate (SPC). Juvenile fish (initial BW 72 g) were fed for 20 weeks on SPC diets supplemented with taurine at levels of 0, 1.0, and 2.0%. In the taurine-unsupplemented SPC diet group, specific growth rate (SGR) and feed conversion ratio (FCR) were significantly inferior (P < 0.001), and incidence of green liver was observed in 70% of fish. In this group, hepatopancreatic and plasma taurine concentrations were lowest (P < 0.05), hepatopancreatic content of bile pigments was highest (P < 0.05), and osmotic tolerance of erythrocytes was inferior (P < 0.05) among the dietary treatment groups. Serum osmolality of all treatment groups was at similar levels. These physiological abnormalities as well as SGR and FCR were improved by dietary taurine supplementation. These results indicate that the mechanism for induction of green liver symptom is bile pigment overproduction due to increased hemolysis because erythrocytes become osmotically fragile due to dietary taurine deficiency. Taurine supplementation of SPC diets is essential for maintaining normal physiological condition and growth performance in juvenile red sea bream.     

Intraspecific diversity of <Emphasis Type="Italic">Undaria pinnatifida</Emphasis> (Harvey) Suringar (Laminariales,Phaeophyta) from Japan,China and Korea,based on the <Emphasis Type="Italic">cox1</Emphasis> gene and ITS2 sequences

As a trial to develop a method of authenticating the place of origin of circulated Undaria pinnatifida products, we investigated their intraspecific genetic diversity using the mitochondrial cytochrome c oxidase subunit 1 gene (cox1) and the internal transcribed spacer 2 (ITS2) region of the nuclear ribosomal DNA (rDNA) sequence. Four dried U. pinnatifida products labeled with their origins (one from Japan, one from China and two from Korea), natural plants collected from three locations (two from Japan and one from China), and cultivated plants collected from two locations (one from Japan and one from China) were used in the present study. The amplified fragments of cox1 were 664 bp in length, and the aligned sequences were highly homologous. Among the nine sequences, no insertions or deletions were found and six substitution positions were detected, and they were classified into five haplotypes. In contrast, multiple highly variable regions were found in ITS2, and some of them carried a restriction site for Mbo II. Polymerase chain reaction-restriction fragment length polymorphism analysis showed different restricted profiles among the tested samples. The availability of molecular markers for authenticating food products of U. pinnatifida is discussed.