Establishment of a pair of novel cloned tumour cell lines with or without metastatic potential from canine mammary adenocarcinoma

We produced 23 cloned cell lines from parental CHMp, which was previously established from a canine mammary adenocarcinoma patient in our laboratory. Two representative cloned cell lines, namely, CHMp-5b and -13a, were selected and characterized for cellular morphology, growth potential and expression of some tumour-related proteins. Subsequently, we transplanted the 2 tumour cell lines orthotopically into female nude mice to examine their tumorigenicity and metastatic potential. Interestingly, despite sharing the same origin, only CHMp-5b cells metastasized to the lung. Our results indicate that a comparison between these 2 cell lines at the molecular level will help us understand mechanisms of tumour progression, especially in the context of distant metastases originating from canine mammary gland tumours.     

Cloning and characterization of 5 MADS-box cDNAs isolated from citrus fruit tissue

We isolated and characterized 5 MADS-box cDNA clones of CitMADS1, CitMADS3, CitMADS5, CitMADS6 and CitMADS8 from fruit tissues of Satsuma mandarin (Citrus unshiu Marc.). Sequence analysis revealed that they have high sequence identities with known MADS-box genes and that their predicted proteins possess the general structural features of the M domain and the K domain. In a phylogenetic tree with 24 known Arabidopsis MADS-box genes, 5 Citrus MADS-box genes were classified into 4 clades of the MADS-box gene with independent gene functions. Their broad expression profiles in the Citrus life cycle suggested that they play roles in flower and fruit development. Most of them, except CitMADS1 and CitMADS3, are expressed in seedlings before the phase transition from vegetative to reproductive growth. CitMADS1 and CitMADS3 are not expressed in vegetative organs and could serve as a molecular marker for reproductive development.     

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.     

Utilization of genetically modified soybean meal in Nile tilapia <Emphasis Type="Italic">Oreochromis niloticus</Emphasis> diets

The utilization of genetically modified soybean meal (GM SBM) was compared with that of non-GM SBM in Nile tilapia. Four experimental diets were formulated to include either non-GM or GM SBM at 34 or 48%, respectively. These diets were fed to juvenile Nile tilapia (49.5 g average weight) for 12 weeks. The uptake of the cauliflower mosaic virus 35S promoter fragment of the GM SBM in fish muscle was examined at 8th and 12th week. After 12th week, fish were fed the non-GM SBM diets to determine the residual span of the incorporated promoter fragment. There was no significant difference in specific growth rate or feed efficiency between GM and non-GM groups at the same inclusion level. A small number of muscles from fish receiving both levels of GM SBM diet were positive for the promoter fragment. Additionally, the promoter fragment was not detected by the second day after changing to the non-GM SBM diets. These results indicate that the utilization of GM SBM was similar to that of non-GM SBM and the promoter fragment was rarely found in fish muscles, suggesting that suitability and safety of GM SBM in Nile tilapia diet were similar to those of non-GM SBM.     

Severe oxidative stress is thought to be a principal cause of jaundice of yellowtail Seriola quinqueradiata

The jaundiced yellowtail Seriola quinqueradiata had yellow discolored skin and hyperbilirubinemia. Histology revealed that hemosiderin and ceroid occurred in the spleen. In the vascular system, there were vasculitis and sinusoidal dilatation. Hepatic cells showed degenerative figures with pyknotic or karyolytic nuclei, basophilic cytoplasm, cytoplasmic vacuoles in various sizes, and ceroidosis. In the bile duct system, however, there was no noticeable change. Hemoglobin contents of jaundiced fish were similar to those of control fish. Plasma taurine levels of jaundiced fish were significantly lower than those of control (p0.05). Judging from 2-thiobarbituric acid reactive substance values, in vivo lipid peroxidation progressed in the liver of jaundiced fish. In the plasma of jaundiced fish, contents of unconjugated bilirubin were significantly higher than those of conjugated bilirubin. A large amount of substance Xs, breakdown products of bilirubin scavenging active oxygen species, existed in the plasma of jaundiced fish. Therefore, jaundiced fish may suffer from severe oxidative stress, which might be a principal cause of jaundice. Liver superoxide dismutase and glutathione peroxidase activities of jaundiced yellowtail were significantly lower than those of controls.     

Performance of Oreochromis niloticus in recirculating aquaculture systems at different levels of daily protein intake

Recirculating aquaculture systems (RASs) are an efficient method for developing sustainable aquaculture and the development of a feed strategy for RASs could be a key factor for the success of culturing Oreochromis niloticus. The daily protein intake (DPI) mathematical function related to body weight (BW) was designed (DPI = ?3.818 ln (BW) + 30.158) named DPI 1.0 = 100%. Three feeding rates were established, DPI 1.4, 1.2 and 1.0, and were implemented in an RAS production cycle (100 fish/m³) for 34 weeks. The final growth measurements were 908.0 ± 57.9 g (DPI 1.4), 887.0 ± 113.5 g (DPI 1.2) and 702.2 ± 38.1 g (DPI 1.0) (p < .05), with feed conversion rates (FCRs) of 2.3, 1.9 and 1.9, respectively; the survival was ≥ 98.3% (p > .05) for all treatments. DPI levels conditioned the growth of the fish and the proportion of lipid: protein in the bodies of O. niloticus but not in the fillets. The mathematical function DPI 1.2 = 120% (DPI = ?4.582 ln (BW) + 36.19) used in the RAS at the 40% protein level improved fish growth, the protein efficiency ratio and FCRs. The DPI values were estimated for 49 different cases and feeding strategies showed lower values than most of the different DPI mathematical functions used and cited in this work. Therefore, DPI metric is a good tool that provides the specific requirements of protein for O. niloticus growth, which can enable farmers to ration feed and improve energy use (kWh / fish) and facilitate the integration of RAS with horticulture.     

Association of early juvenile yellowfin tuna <Emphasis Type="Italic">Thunnus albacares</Emphasis> with a network of payaos in the Philippines

To understand how early juvenile yellowfin tuna use the habitat and environment provided by fish aggregating devices (FADs), fish (19–31 cm FL) implanted with ultrasonic transmitters into their abdominal cavities were released in a network of payaos in Panay Gulf, the Philippines. Self-recording receivers were attached to the anchor ropes of the payaos to detect the presence of the fish. Some aspects of the behavior of juveniles were similar to those reported in adults. One juvenile showed a diurnal vertical swimming pattern, swam within a limited shallow range during the nighttime, and dived to deeper waters during the daytime. Two juveniles performed deep dives over 100 m during payao-to-payao excursion. Three juveniles showed a diurnal horizontal swimming pattern that was synchronized. In contrast, juveniles stayed <6 days in the network, shorter than adults. No juveniles returned to the same payao after an interruption of over 24 h. It is suggested that juveniles in this area are just starting to migrate and are temporarily staying around a payao for a few days to forage before continuing their migration.     

Development of a label-free immunosensor system for detecting plasma cortisol levels in fish

Fishes display a wide variation in their physiological responses to stress, which is clearly evident in the plasma corticosteroid changes, chiefly cortisol levels in fish. In the present study, we describe a novel label-free immunosensor for detecting plasma cortisol levels. The method is based on immunologic reactions and amperometric measurement using cyclic voltammetry. For the immobilization of the antibody on the surface of sensing electrode, we used a self-assembled monolayer of thiol-containing compounds. Using this electrode, we detect the CV signal change caused by the generation of antigen–antibody complex. The immunosensor showed a response to cortisol levels, and the anodic peak value linearly decreased with a correlation coefficient of 0.990 in diluted plasma. The specificity of the label-free immunosensor system was investigated using other steroid hormones, such as 17α, 20β-dihydroxy-4-pregnen-3-one, progesterone, estriol, estradiol, and testosterone. The specific detection of cortisol was suggested by a minimal change from ?0.32 to 0.51 μA in the anodic peak value of the other steroid hormones. The sensor system was used to determine the plasma cortisol levels in Nile tilapia (Oreochromis niloticus), and the results were compared with those of the same samples determined using the conventional method (ELISA). A good correlation was obtained between values determined using both methods (correlation coefficient 0.993). These findings suggest that the proposed label-free immunosensor could be useful for rapid and convenient analysis of cortisol levels in fish plasma samples.