New type of heat shock protein 70 homologue gene abounds in the genomic sequence of kuruma shrimp Marsupenaeus japonicus

Heat shock proteins (HSPs) are a group of highly conserved molecular chaperones. Shrimp HSPs have recently been a topic of increasing interest because of their roles in shrimp immunity and homeostasis. In penaeid shrimp, HSP70s and the cognate forms, heat shock cognate (HSC) 70s, have been reported, but their responses towards various stimulations are different. We found a novel type HSP70 (MjHSP70-2) from the hyperexpansion of the large segmental duplication that is present in kuruma shrimp Marsupenaeus japonicus, which shows about 60 % identity with reported shrimp HSP70s. In a phylogenetic tree, MjHSP70-2 formed a sister clade with eukaryote HSP70 family while MjHSP70 was located close to the shrimp HSP70 and HSC70 group. MjHSP70-2 gene expression was not significantly increased by heat shock or pathogen challenge by Vibrio penaeicida, but it was significantly increased by infection with white spot syndrome virus. In contrast, MjHSP70 gene expression was increased by heat shock but decreased by infection with V. penaeicida. The kuruma shrimp genome was found to have 400-fold more copies of the MjHSP70-2 gene than the putative single-copy gene transglutaminase. In conclusion, our results reveal the presence of a novel type HSP70 gene, HSP70-2, from kuruma shrimp. There are multiple forms of HSP70 in crustaceans, and these HSP70s behave differently under various stressors.     

Assessment of decay risk of airborne wood-decay fungi

The decay risk of airborne wood-decay fungi was investigated by using an air sampler. Japanese cedar disks 7.8 cm in diameter and about 3 mm in thickness with moisture content of about 100% were placed in a “BIOSAMP” air sampler and exposed to 1000 l air. Air sampling was carried out from June to September at the same sampling site in Tsukuba, Japan. The exposed disks were then incubated for 16 weeks in a damp container kept at 26° ± 2°C. During the incubation period, wood mass loss ranged from −15 to 807 mg with a mean mass loss of 244 mg. Factors affecting mass loss were explored. Wood moisture content and ratio of heartwood area proved to be significant factors. In addition, six weather factors were found to influence mass loss. Disks that were sampled on a cloudy day showed significantly higher mean mass loss compared to those sampled on a sunny day. Subculturing of filamentous fungi from 16-week incubated disks suggested one-third of the isolated fungi produced ligninolytic enzymes.     

Effect of feeding sweet‐potato condensed distillers solubles on intake and urinary excretion of minerals in Japanese Black steers

Four Japanese Black steers (16 months of age) were assigned to a 4 × 4 Latin square design to investigate the effect of graded levels of sweet‐potato condensed distillers solubles (SCDS) in their diets on intake and urinary excretion of minerals. The four diets consisted of 0%, 10%, 20% and 30% (dry matter (DM) basis) SCDS, with SCDS replacing commercial concentrate (CC). Intake of K, Cl, S, P and Mg increased linearly with increasing SCDS content. Urinary pH increased linearly with increasing dietary SCDS content. SCDS feeding increased urinary K concentrations (linear and quadratic effects). Urinary concentrations of Cl increased linearly with increasing SCDS content. In contrast, urinary concentrations of Mg decreased with increasing SCDS content. Feeding of SCDS did not apparently affect urinary NH₃,P, Na or Ca concentrations. These results suggest that high SCDS feeding is not a risk for crystallization of minerals leading to the formation of magnesium‐phosphate type calculi: although SCDS contains large amounts of P and Mg, high SCDS feeding decreased the Mg concentration and did not affect the P concentration in urine. Additionally, high SCDS feeding had no apparent effects on plasma concentrations of Na, K, Cl, Ca or inorganic P.     

Production and characterization of inter-sectional hybrids between <Emphasis Type="Italic">Kalanchoe spathulata</Emphasis> and <Emphasis Type="Italic">K. laxiflora</Emphasis> ( = <Emphasis Type="Italic">Bryophyllum crenatum</Emphasis>)

The genus Kalanchoe is currently divided into section Kalanchoe and section Bryophyllum, and there has been no successful report on the production of inter-sectional hybrids. Therefore, reciprocal crosses were made between Kalanchoe spathulata (sect. Kalanchoe) and K. laxiflora (sect. Bryophyllum) in order to obtain basic information on the reproductive barriers between these two sections. The seeds were aseptically germinated in vitro and the plants were grown in greenhouse till flowering. When K. spathulata was used as a maternal donor, 39 out of 80 plants showed intermediate characteristics between K. spathulata and K. laxiflora. In contrast, no plants were obtained in the reverse crosses. Hybridity of these plants was confirmed by flow cytometric analysis, chromosome numbers and RAPD analysis. Bulbil formation on the leaf margin as one of the conspicuous characteristics of K. laxiflora was not observed in the hybrids. Some of the hybrid lines showed some pollen fertility, but failed to yield viable seeds by self-pollination or backcross-pollination. Successful production of the inter-sectional hybrid between the two species suggests that they are not so distantly related as considered previously.     

Effect of drying method as a pretreatment on CUAZ preservative impregnation in Japanese cedar logs

Green Japanese cedar logs 2 m in length and 18 cm in diameter were dried to a mean moisture content of less than 30% by either air drying or kiln drying. Dried logs were impregnated with copper azole (CUAZ) solution according to Japanese Industrial Standard (JIS) A9002. Preservative absorption was calculated from the log weight before and after preservative impregnation. Impregnated logs were then dried in the air and cut at the center to determine preservative penetration. The penetration area was determined after visualizing the preservative with chrome azurol S. The visualized area indicated that the preservative solution penetrated into the sapwood portion of almost all the air-dried logs. However, the kiln-dried logs did not show full penetration into the sapwood portion. The visualized area of some kiln-dried sapwood showed a penetration value of less than 80%, which is the minimum requirement set by the Japanese Agricultural Standard (JAS) for sawn timber. Statistical analysis showed that penetration in the air-dried sapwood was significantly better than that in the kiln-dried sapwood. It was concluded that air drying is more favorable than kiln drying as the predrying method for CUAZ impregnation. On the other hand, preservative absorption was not affected by the drying method.     

Dimethoxypyrimidines as Novel Herbicides. Part 2. Synthesis and Herbicidal Activity of O-Pyrimidinylsalicylates and Analogues

A new series of the O-pyrimidinylsalicylates was synthesized and their herbicidal activity was examined. Some of these compounds showed very strong herbicidal activity under pre- and post-emergent treatment conditions against various kinds of grass and broadleaf weeds. Among these compounds, O-(4, 6-dimethoxypyrimidin-2-yl) salicylic acid and its methyl ester were found to exhibit the highest activity. The herbicidal symptoms observed after the treatments included early cessation of plant growth followed by chlorosis, necrosis and plant death. The symptoms were similar to those caused by sulfonylureas and imidazolinones, which inhibit branched-chain amino acid biosynthesis.     

Dietary 5‐aminolevulinic acid enhances adenosine triphosphate production,ecdysis and immune response in Pacific white shrimp,Litopenaeus vannamei (Boone)

Previous studies have shown that 5‐aminolevulinic acid (5‐ALA), a precursor of haem, can enhance haem synthesis and the activity of haemoproteins. Here, we investigated the effects of dietary 5‐ALA on Pacific white shrimp, Litopenaeus vannamei (Boone). Dietary groups included basal diet (BD, control) and BD plus 15, 30 and 60 ppm 5‐ALA (ALA15, ALA30 and ALA60 respectively). Hepatopancreas adenosine triphosphate (ATP) levels increased with increasing 5‐ALA concentration (ALA60 p < 0.05) after 2 weeks of feeding. 5‐aminolevulinic acid diets significantly increased the expression of ecdysis‐related genes: nuclear receptor E75 and chitinase 4 (ALA15, ALA30, ALA60), cytochrome P450 Shade (ALA60), chitinase 1 (ALA60) and chitinase 3 (ALA15, ALA60). Catalase (CAT) and prophenoloxidase gene expression levels were also significantly higher in ALA60 after 12 weeks of feeding. Six hours after L. vannamei were exposed to Vibrio parahaemolyticus, total haemocyte count (ALA60) and gene expression levels of CAT (ALA30, ALA60) were significantly higher in 5‐ALA groups compared to the control. 5‐aminolevulinic acid diets also increased survival of L. vannamei following V. parahaemolyticus immersion challenge. These results suggest that supplementing L. vannamei diets with 5‐ALA can enhance ATP production, immune response against V. parahaemolyticus, total haemocyte count and expression of some immune‐related genes. 5‐aminolevulinic acid can also induce ecdysis‐related gene expressions, without adversely affecting growth.     

Myxosporean and microsporidian infections in cultured Pacific bluefin tuna <Emphasis Type="Italic">Thunnus orientalis</Emphasis> in Japan

During the parasitological survey of cultured juvenile Pacific bluefin tuna (PBT) Thunnus orientalis in 2007 and 2008, two myxosporeans and one microsporidian were found. Morphological and molecular analysis showed that the heart-infecting and brain-infecting myxosporeans are identified as Kudoa shiomitsui and K. yasunagai, respectively. This is a new host record for both species. High prevalence of infection (77–100%) with K. shiomitsui was observed in October to December (1–2 months post-transfer to sea cages), whereas only a few fish were infected with K. yasunagai. A microsporidian observed as white “cysts” in the trunk muscle of PBT had a resemblance to Microsporidium seriolae, the causative parasite of beko disease in yellowtail. Phylogenetic analysis showed that the microsporidian from PBT is closely related to but distinct from several other muscle-infecting species such as M. seriolae, Microsporidium sp. RSB, and Microsporidium sp. SH. Additionally, the spore dimension (2.7 × 1.5 μm on average) was remarkably smaller than the others. These results suggest that the present microsporidian is an undescribed species and designated Microsporidium sp. PBT. Prevalence and intensity of infection with Microsporidium sp. PBT reached a maximum of 100% and 20 cysts/fish, respectively. Although pathogenic effects of the two Kudoa species on fish health remain unknown, the microsporidian could be of concern to PBT aquaculture due to unsightly cysts in the musculature, reducing the market value of the fish.     

Suitability of genetically modified soybean meal in a dietary ingredient for common carp Cyprinus carpio

The effect of genetically modified (GM) soybean meal (SBM) in a feed ingredient on growth performance of common carp was investigated in comparison to nonGM SBM. GM SBM was included at 34 and 48% in two experimental diets that were formulated with fish meal (FM) to obtain approximately 38% protein in diet. Two other experimental diets were formulated to contain the same levels of nonGM SBM. The diets were fed to juvenile common carp (22 g initial mean weight) for 12 weeks. The cauliflower mosaic virus (CaMV) 35S promoter fragment (205 base pairs) of the GM SBM was examined in fish muscle and blood samples at the twelfth week. From the twelfth week, the GM groups were fed with nonGM diets to determine the residual span of the transferred promoter fragment. There was no significant difference in growth and feed performance between GM and nonGM groups at two inclusion levels after 12 weeks. The CaMV 35S promoter fragment was not detected in fish muscles or blood receiving either level of GM SBM diet. The results demonstrated that the availability of GM SBM was similar to that of nonGM SBM and the GM SBM would be a suitable and safe ingredient in feed for common carp.     

Convenient Method to Determine Free Fatty Acid of Rice Using Thin‐Layer Chromatography and Flame‐Ionization Detection System

A convenient method which possessed simplicity and high sensitivity was designed to investigate the changes in free fatty acid (FFA) of rice during storage using a thin‐layer chromatography and flame‐ionization detection (TLC/FID) system. In this method, two different solvent systems for TLC were used according to the purpose of experiments. Solvent system A (hexane and diethyl ether and acetic acid 80:20:1) was suitable to obtain a chromatogram showing the overall state of rice lipid degradation. Using solvent system A, the degradation of triglyceride or the increase in FFA during storage was clearly visualized as changes in the chromatogram. Solvent system B (hexane and acetic acid 100:1) was used to improve the low reproducibility of the TLC/FID method. When methyl stearate was used as an internal standard with solvent system B, high reproducibility of the FFA value was obtained, and very small changes were detectable in stored white milled rice. This method has small sample size and simple operation and is more sensitive than the standard titration method. Therefore, this seems to be an especially convenient method for small‐scale storage tests or for experiments using many samples.