Presence of infectious salmon anaemia virus (ISAV) in tissues of Atlantic salmon, Salmo salar L., collected during three separate outbreaks of the disease     

A. NYLUND  T. HOVLAND  K. WATANABE  C. ENDRESEN 《Journal of fish diseases》1995,18(2):135-145

Abstract. Infectious salmon anaemia (ISA) is a viral disease of farmed Atlantic salmon, Salmo salar L., in Norway. The enveloped virus particles (100nm) believed to be the causative agent of the disease have been observed budding from endothelial cells in heart blood vessels. However, it is not known if the virus propagates in endothelial cells in all tissues/organs, if other target cells exist or if material collected from different salmon farms with natural outbreaks of ISA contain the same virus particles. Salmon smolts from three hatcheries with no history of disease were taken into the laboratory and experimentally challenged with ISA collected from Atlantic salmon during natural outbreaks of the disease in three different fish farms outside Bergen. Norway. Tissues for TEM studies were Collected from: (1) organs that showed clinical signs of ISA (i.e. used in the diagnosis of the disease); (2) tissues believed to be important in transmission of the virus (integument, kidney, urinary bladder, gut and somatic muscle); and (3) hormone-producing tissues (pituitary gland, saccus vasculosus, thymus, thyroid, ultimobranehial gland, gonad, head kidney, heart and ventral aorta). The same virus as that believed to be the causative agent of ISA was found in all tissues examined from the challenged fish, i.e. a multiorgan infection with the same virus present in salmon from all three fish farms. The virus particles are about 100 nm in diameter, consisting of a slightly pleomorphic unit membrane envelope within which are a number of granules about 10–12nm in diameter. The granules seemed to be arranged in two concentric circles (spheres). The virus was seen budding from the surface of endothelial cells in blood vessels/sinus only. However, the virus was found intracellularly in both endothelial cells and in leucocytes.  相似文献   

Production of docosahexaenoic acid bounded phospholipids via phospholipase A2 mediated bioconversion     

Shinichi Awano  Koji Miyamoto  Masashi Hosokawa  Mitsumasa Mankura  Koretaro Takahashi 《Fisheries Science》2006,72(4):909-911

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On the relationship between the Oyashio front and saury fishing grounds in the north-western Pacific: a forecasting method for fishing ground locations   总被引：1，自引：0，他引：1  

ICHIRO YASUDA  YOSHIRO WATANABE 《Fisheries Oceanography》1994,3(3):172-181

The relationships between fishing ground locations of Pacific saury (Cololabis saira) and the two Oyashio fronts, the offshore front between 146^oE and 155^oE and the coastal Oyashio intrusion, before the saury fishing season, were examined using data from 1971 to 1991. Interannual geographical shifts of both the offshore Oyashio front and saury fishing grounds had a dominant interdecadal fluctuation. In years when the offshore front shifted north (south), the fishing grounds were formed relatively nearshore (offshore). When the offshore front shifted north, the fishing grounds were formed further nearshore in years the coastal Oyashio intrusion extended south. When the offshore front shifted south, on the other hand, the southward extension of the coastal intrusion did not necessarily cause formation of coastal fishing grounds. These results showed that locations of the fishing grounds depend not only on local and instantaneous oceanographic environments around the fishing grounds, but also on oceanographic conditions over an extensive range of the Oyashio area. This might indicate that the ecology of the saury's northward migration, through mixed water regions between the Kuroshio and Oyashio fronts in spring and summer, has a close relation to the shift of the offshore Oyashio front over a time range of months. A practical forecasting method for locations of saury fishing grounds is proposed based on the oceanography before the fishing season.  相似文献   

Myxobolus aeglefini found in the skeletal muscle of porous-head eelpout Allolepis hollandi from the Sea of Japan     

Hiroshi Yokoyama  Shinichi Wakabayashi 《Fisheries Science》2000,66(5):963-966

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Reassessment of phosphorus and nitrogen discharge from commercial carp feeds     

PARVEEN  JAHAN  TAKESHI  WATANABE  VISWANATH  KIRON  SHUICHI  SATOH 《Fisheries Science》2003,69(1):117-123

ABSTRACT:   The present study, one in a series to clarify the phosphorus (P) and nitrogen (N) loading from carp culture, evaluated four commercial diets. The total and available P in these diets varied from 1.57 to 1.86% and from 0.38 to 0.87%, respectively. The control diet, selected based on an earlier experiment, contained 1.40% total P and 0.68% available P. The 7-week feeding trial was performed with juvenile carp. Superior feed gain ratio was obtained for the control diet (1.00) and it varied from 1.19 to 1.56 among the commercial diet groups. Similarly, the control diet showed higher rates of P absorption (43.8%) and retention (33.1%) than the rest (absorption: 18.1–40.9%; retention: 10.7–18.7%). Total P loading (kg/t production) was 10.0 for the control group but ranged from 19.1 to 25.0 among the commercial diet groups. Nitrogen absorption was not markedly different; however, fluctuations in retention resulted in N loading (kg/t production) that ranged between 47.1 and 66.3 among the commercial diets, higher than the 34.8 obtained for the control diet. The available P in the commercial diets rarely matched the requirement level, thereby negatively affecting the waste loading. The superior performance of the control diet underscores the fact that effective formulations help in keeping emission levels low.  相似文献   

Different combinations of protein ingredients in carp diets for reducing phosphorus loading     

Parveen  JAHAN  Takeshi  WATANABE  Shuichi  SATOH  Viswanath  KIRON 《Fisheries Science》2002,68(3):595-602

ABSTRACT: This study was conducted to gather data on the reduction of environmental phosphorus (P) loading through the formulation of carp diets with different combinations of protein ingredients. Five experimental diets were formulated by substituting fishmeal (FM; 10–20%) with alternative protein sources such as meat meal (MM; 5–15%), blood meal (BM; 5–7%), and defatted soybean meal (dSBM; 6–10%). The control diet used was a commercial carp diet selected based on earlier experiments. Each diet was fed to duplicate groups of juvenile carp three times a day, until satiation for 12 weeks. Feed performance was proportional to the increase in dietary FM levels. Phosphorus absorption ranged between 41.6% and 52.0% among the experimental groups and was 42.6% for the control group, but there were no marked differences in nitrogen (N) absorption rates. Phosphorus retention ranged from 31.4% to 35.7% for the test diets, whereas N retention increased proportionally with dietary FM levels and ranged from 34.7% to 41.7%. The P and N retention values of the control diet were 27.6% and 41.2%, respectively. The total P loading (T-P) increased at the higher FM levels (9.1–10.7 kg/t production), whereas lower FM levels produced higher total N loading (T-N, 34.6–43.1 kg/t production), the figures for the control being 13.9 T-P kg/t production and 35.6 T-N kg/t production. These results indicate that the reduction of FM levels to 10–20% by replacing it with MM, BM, and dSBM in carp diets was effective in reducing the loading of P and N.  相似文献   

Analysis of concrete strength effective factors of diagonal strutmechanism on frame exterior beam-column joints     

CUI Jian-yu  SUN Jian-gang  SONG Yu-pu  WATANABE Fumio 《保鲜与加工》2011,(4):107-112

This paper uses the strut-truss model to analyze the shear strength of reinforced concrete frame exterior joints through thirty-five shear failure type joints without beam flexural yield and six shear failure joints after beam flexural yield.It discusses the influence of parameters including concrete compressive strength,column axial-compression ratio,amount of joint horizontal or vertical hoop,and angle of strut mechanism etc.,on concrete strength effective factor ρ of diagonal strut mechanism.The analysis results show that ρ value deterioration ratio at peak load increases with the increase od concrete strength.The effect of joint hoop on ρ value deterioration is more significant using ordinary strength concrete than the case using high strength concrete.The contribution of strut mechanism to joint shear force is more than 80% when joint shear reinforcement ration is less than 0.3%.The joint strength equation is proposed based on the analysis results of the factor ρ,and the calculated values agree well with the experimental results.  相似文献   

The ecoresponsive genome of Daphnia pulex     

Colbourne JK  Pfrender ME  Gilbert D  Thomas WK  Tucker A  Oakley TH  Tokishita S  Aerts A  Arnold GJ  Basu MK  Bauer DJ  Cáceres CE  Carmel L  Casola C  Choi JH  Detter JC  Dong Q  Dusheyko S  Eads BD  Fröhlich T  Geiler-Samerotte KA  Gerlach D  Hatcher P  Jogdeo S  Krijgsveld J  Kriventseva EV  Kültz D  Laforsch C  Lindquist E  Lopez J  Manak JR  Muller J  Pangilinan J  Patwardhan RP  Pitluck S  Pritham EJ  Rechtsteiner A  Rho M  Rogozin IB  Sakarya O  Salamov A  Schaack S  Shapiro H  Shiga Y  Skalitzky C  Smith Z  Souvorov A  Sung W 《Science (New York, N.Y.)》2011,331(6017):555-561

We describe the draft genome of the microcrustacean Daphnia pulex, which is only 200 megabases and contains at least 30,907 genes. The high gene count is a consequence of an elevated rate of gene duplication resulting in tandem gene clusters. More than a third of Daphnia's genes have no detectable homologs in any other available proteome, and the most amplified gene families are specific to the Daphnia lineage. The coexpansion of gene families interacting within metabolic pathways suggests that the maintenance of duplicated genes is not random, and the analysis of gene expression under different environmental conditions reveals that numerous paralogs acquire divergent expression patterns soon after duplication. Daphnia-specific genes, including many additional loci within sequenced regions that are otherwise devoid of annotations, are the most responsive genes to ecological challenges.  相似文献   

DNA methylation analysis on satellite I region in blastocysts obtained from somatic cell cloned cattle     

Ken‐ichi YAMANAKA  Masahiro KANEDA  Yasushi INABA  Koji SAITO  Kaiyu KUBOTA  Miki SAKATANI  Satoshi SUGIMURA  Kei IMAI  Shinya WATANABE  Masashi TAKAHASHI 《Animal Science Journal》2011,82(4):523-530

Many observations have been made on cloned embryos and on adult clones by somatic cell nuclear transfer (SCNT), but it is still unclear whether the progeny of cloned animals is presenting normal epigenetic status. Here, in order to accumulate the information for evaluating the normality of cloned cattle, we analyzed the DNA methylation status on satellite I region in blastocysts obtained from cloned cattle. Embryos were produced by artificial insemination (AI) to non‐cloned or cloned dams using semen from non‐cloned or cloned sires. After 7 days of AI, embryos at blastocyst stage were collected by uterine flushing. The DNA methylation levels in embryos obtained by using semen and/or oocytes from cloned cattle were similar to those in in vivo embryos from non‐cloned cattle. In contrast, the DNA methylation levels in SCNT embryos were significantly higher (P < 0.01) than those in in vivo embryos from non‐cloned and cloned cattle, approximately similar to those in somatic cells used as donor cells. Thus, this study provides useful information that epigenetic status may be normal in the progeny of cloned cattle, suggesting the normality of germline cells in cloned cattle.  相似文献   

Detection and quantification of protein residues in food grade amino acids and nucleic acids using a dot-blot fluorescent staining method     

Yamada N  Ozawa S  Kageyama N  Miyano H 《Journal of agricultural and food chemistry》2004,52(17):5329-5333

Food allergies represent an important health problem in industrialized countries, such that detection and quantitative analysis of the protein considered to be the main allergen is crucial. A dot-blot fluorescent staining method for the detection and quantitative analysis of protein residues in food grade amino acids and nucleic acids is presented. This method combines fluorescence staining with dot-blotting onto PVDF membrane. Several standard proteins, such as bovine serum albumin (66 kDa), lysozyme (14 kDa), ubiquitin (8.6 kDa), bovine insulin (5.7 kDa), and oxidized insulin B chain (3.5 kDa), were detectable at 0.1 ppm using SYPRO Ruby blot stain. Twenty-five different amino acids and two different nucleic acids of food grade were analyzed using this method combined with an internal standard addition method using BSA as an internal standard. All amino acids and nucleic acids were dissolved in 3.6% aqueous HCl and dot-blotted onto PVDF membrane before a large amount of amino acids and nucleic acid were removed. Protein residues and the internal standard protein immobilized on the membrane were stained using SYPRO ruby blot stain. The internal standard in all samples was detectable at 0.1 ppm. Samples were dissolved at 120 or 70 mg/mL, according to their solubility under acidic conditions. The detection limit of protein residues per weight was 0.8-1.4 ppm in amino acids and nucleic acids; residual protein was not detected in any sample.  相似文献