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2.
Two bacterial strains, Lactobacillus fructivorans, isolated from sea bream (Sparus aurata) gut, and Lactobacillus plantarum, isolated from human faeces, were administered simultaneously, during sea bream development, using Brachionus plicatilis and/or Artemia salina as vectors. The probiotic treatment significantly affected gut colonization. To test the probiotic influence on stress responsiveness, sea bream fry, 47 days post-hatching (p.h.), were subjected to pH stress (from 8.6 to 6.3) and cumulative mortality, cortisol levels and HSP70 gene expression were analysed. Cortisol was selected, since under stress conditions its level increases. HSP70 was selected with consideration of its wide involvement in response to a great number of injuries, and because it protects cells probably by binding and refolding damaged proteins. The results obtained indicated that the administration of probiotic to sea bream fry induced higher HSP70 levels, indicating a greater potentiality to respond to the harmful conditions possibly present in fish farms. This hypothesis is supported by the fact that the levels of cortisol found were significantly lower (P < 0.05) in both groups under probiotic treatment. When pH was used as a stressor, it induced a higher cumulative mortality in the control; the mortality was found to be significantly lower in both treated groups. Interestingly, a significant increase (P < 0.05) in HSP70 gene expression was observed in all stressed groups. These results suggest an improvement in tolerance to acute stress of fry fed with probiotics.  相似文献   

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4.
Expression of HSP70 in response to heat-shock was investigated at the protein and mRNA levels in Mediterranean blue mussel. Western and Northern blot analyses revealed that HSP70 was expressed following heat-shock in the mantle at both protein and mRNA levels, suggesting that gene expression of HSP70 is implicated in the cellular response to heat-shock stress in mussel. It was then attempted to clone HSP70 cDNA in order to determine the primary structure of mussel HSP70. As a result, two full-length cDNA encoding HSP70 were isolated from a cDNA library prepared from the heat-shocked mantle. The isolated cDNA consist of single open reading frames of 2067 bp and 1911 bp which encode proteins of 689 amino acids and 637 amino acids, respectively. Both HSP70 cDNA encode an ATPase do main, and a substrate-binding do main in addition to a Glu-Glu-Val-Asp (EEVD) peptide motif that is specific for cytosolic HSP70. These findings suggest that the cDNA clones obtained in the present study encode cytosolic HSP70.  相似文献   

5.
《水生生物资源》1999,12(1):23-30
The common dentex (Dentex dentex) is a sparid fish which is considered a suitable candidate for Mediterranean aqua-culture. A seven-weeks feeding trial was conducted over the summer period with common dentex, sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax). All three species were fed to visual satiety with two practical diets with varying crude protein and crude fat levels (55 % protein, 9 % lipids; 46 % protein, 17 % lipids). The initial body weights were 8.2, 11.6 and 17.3 g for common dentex, sea bass and sea bream, respectively. In all cases, specific growth rates were not significantly affected by dietary treatment, but they varied among species (sea bass 1.7–1.8 %; sea bream 2.1–2.3 %; common dentex 3.1–3.2 %). When comparisons between fish species were made, we observed that the increase in growth rates was linked to a decrease of the whole body fat content, as a consequence of a greater utilisation of dietary lipids as energy substrates. Furthermore, in common dentex, the 17 % lipid diet was able to improve protein retention, but this diet effect was less significant in sea bream and sea bass. In contrast to sea bream, the 17 % lipid diet did not up-regulate plasma GH levels in common dentex, which provides additional evidence for a more efficient utilisation of dietary lipids.  相似文献   

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7.
The aim of the present study was to compare the expression pattern of heat-shock protein 60 (HSP60), 70 (HSP70), and 90 (HSP90) mRNA in hepatic cells of grass carp exposed to enrofloxacin and emodin concentrations. The expression pattern of different genes encoding heat-shock proteins in hepatic cells of grass carp was exposed to graded levels of enrofloxacin (12.5, 25, 50, 100, and 200 μg/ml) or emodin (0.04, 0.2, 1, 5, and 25 μg/ml) for 24 h and were investigated by real-time quantitative PCR. When cells were exposed to up 50 μg/ml enrofloxacin, both HSP60 and HSP70 mRNA levels firstly were increased and thereafter significantly dropped at high concentrations (P < 0.05), while HSP90 decreased with increasing enrofloxacin concentration. Besides, HSP60 and HSP70 expressions were significantly inhibited in the high-concentration groups. In addition, the HSP90 mRNA levels in the treatment exposed to 100 and 200 μg/ml enrofloxacin were significantly lower than those of the control group (P < 0.05). Furthermore, when cells were exposed to graded levels of emodin, HSPs (HSP60, 70, and 90) mRNA levels significantly increased in the groups exposed to 5 and 25 μg/ml of emodin. The different expression pattern of HSPs implied that enrofloxacin could inhibit the expression levels of HSPs, while optimal level of emodin could trigger higher expression levels of HSPs in hepatic cell of grass carp to protect against further damage.  相似文献   

8.
Growth hormone (GH), prolactin (PRL) and somatolactin (SL) are single chain proteins structurally and functionally related. Fish PRL and GH receptors (PRLR, GHR) have been characterized in several fish species. There is limited evidence of fish PRLR isoforms, but emerging data support the existence of different GHR variants. In gilthead sea bream, black sea bream, turbot and fugu, but not in zebrafish, GHR has retained an exclusive fish intron (10/10A). In gilthead sea bream and turbot, this intron is not alternatively spliced, but the black sea bream intron is either removed or retained during mRNA processing, resulting in a long GHR isoform with a 31 amino acid insertion that does not alter the open reading frame. This or any other GHR variant are not found in gilthead sea bream, but a truncated anchored form has been reported in turbot. The latter GHR isoform comprises extracellular and trans-membrane domains, the first 28 amino acids of the intracellular domain and 21 divergent amino acids before a stop codon. This GHR variant is the result of alternative splicing, being the 3′ UTR and the divergent sequence identical to the sequence of the 5′ end of the 9/10 intron. The physiological significance of different fish GHR isoforms remains unclear, but emerging data provide suitable evidence for season and nutrition related changes in the somatototropic axis activity. The up-regulation of circulating GH together with the decrease of plasma titres of insulin-like growth factor-I (IGF-I), an altered pattern of serum IGF binding proteins and a reduced expression of hepatic IGF-I and GHRs represent a mechanism conserved through vertebrate evolution. It secures the preferential utilization of mobilized substrates to maintain energy homeostasis rather than tissue growth. Somatolactin also changes as a function of season, ration size, dietary amino acid profile and dietary protein source creating opposite plasma GH and SL profiles. There is now direct evidence for a lipolytic effect of fish SL, acting at the same time as an inhibitory factor of voluntary food intake. Indeed, long-term feeding restriction results in the enlargement of the summer GH peak, whereas the SL rise coincident with shortened day length is delayed in juvenile fish until late autumn. These findings agree with the idea that SL may act as a marker of energy surplus, priming some particular process such as puberty onset. However, it remains unclear whether SL works through specific receptors and/or dimers or heterodimers of GH and PRL receptors.  相似文献   

9.
In this study, we exposed black sea bream, Mylio macrocephalus (Basilewsky), fibroblast (BSF) and silver sea bream, Sparus sarba Forsskål, fibroblast (SSF) cell lines to a recombinant Vibrio harveyi haemolysin (VHH) and investigated mechanisms involved in apoptosis. A decrease in mitochondrial membrane potential, followed by an increase in caspase 3 activity, occurred within 2–8 h of VHH exposure, in both cell lines; however, VHH did not alter cellular levels of reactive oxygen species. As heat shock protein 70 (HSP70) is known to prevent the onset of apoptosis in certain mammalian cells, we aimed to test whether such a protective effect is operative in VHH‐exposed fibroblasts. The amounts of HSP70 were elevated in SSF and BSF via an acute heat shock or an acute heat shock followed by a 6 h recovery. It was found that the VHH‐mediated reduction in mitochondrial membrane potential was suppressed in cells that had a 6 h post‐heat shock recovery, and the protective effect of heat shock‐induced HSP70 was attenuated following treatment of cells with the HSP70 inhibitor, quercetin. This study demonstrates how haemolysin causes cell death via induction of apoptosis and provides evidence as to the role of HSP70 as an anti‐apoptotic factor.  相似文献   

10.
The purpose of the trial was to study the impact of a 6‐mo dietary administration of soybean protein on growth, liver and intestine morphology, immune response, and oxidative stress in gilthead sea bream. The immune response was evaluated by performing immunological assays in blood, head kidney (HK), or serum (respiratory burst activity [RBA], myeloperoxidase content and bacteriolytic activity) and gene expression analysis of immune‐associated genes (MHCIIα [major histocompatibility complex IIα], β2m [β‐2‐microglobulin], CSF‐1R [colony‐stimulating factor‐1 receptor], NCCRP‐1 [nonspecific cytotoxic cell receptor protein 1], TGF‐β1 [transforming growth factor beta‐1], and HSP70 [heat‐shock protein 70]) in HK and intestine. Oxidative stress was evaluated by measuring the activity of liver enzymes associated with antioxidant system. The soybean protein was administrated in the diets at 20, 40, and 60% levels and its effects were evaluated compared with a fish meal diet. Growth and feed efficiency were affected negatively from 40% level. Increased RBA and expression levels of TGF‐β1 and β2m were found in HK only at 40% level. In intestine, at 60% level CSF‐1R expression was upregulated and some signs of inflammation were evident. In liver, at 60% level lipid accumulation in hepatocytes was observed and enzyme activity was increased. Dietary administration of soybean protein indicated changes from 40% in growth and immune response, and exerted an antioxidative effect at 60% level.  相似文献   

11.
Japanese people consume crop bran, which contains relatively high amounts of gamma-oryzanol (ORZ), as foodstuffs and food materials. We have recently confirmed that ORZ inhibits NF-κB activation, activates peroxisome proliferator-activated receptor gamma (PPARγ), and increases plasma adiponectin levels. ORZ is therefore expected to improve lipid and carbohydrate metabolisms and various inflammatory diseases, i.e., metabolic syndrome including type 2 diabetes. ORZ administration also allowed fish, such as rainbow trout, yellowtail, and red sea bream, to accumulate protein through enhancement of lipid and carbohydrate metabolisms. In the present study, we have investigated ORZ accumulation levels in mouse and rainbow trout administered ORZ-containing feed. Although mouse muscle and liver hardly contained ORZ, muscle tissues of every fish species accumulated higher amounts of ORZ. These findings suggest that rainbow trout, red sea bream, and yellowtail accumulate ORZ in muscle.  相似文献   

12.
As suggested by the Office International des Epizooties (OIE), fishes belonging to the genus Oplegnathus are more sensitive to megalocytivirus infection than other fish species including red sea bream (Pagrus major). To assess the roles of the innate immune response to these different susceptibilities, we cloned the genes encoding inflammatory factors including IL‐8 and COX‐2, and the antiviral factor like Mx from red sea bream for the first time and performed phylogenetic and structural analysis. Analysed expression levels of IL‐1β, IL‐8 and COX‐2 and the antiviral factor like Mx genes performed with in vivo challenge experiment showed no difference in inflammatory gene expression or respiratory burst activity between red sea bream and rock bream (Oplegnathus fasciatus). However, the Mx gene expression levels in red sea bream were markedly higher than those in rock bream, suggesting the importance of type I interferon (IFN)‐induced proteins, particularly Mx, during megalocytivirus infection, rather than inflammation‐related genes. The in vitro challenge experiments using embryonic primary cultures derived from both fish species showed no difference in cytopathic effects (CPE), viral replication profiles, and inflammatory and Mx gene expression pattern between the two fish species.  相似文献   

13.
Every organism responds to heat stress by synthesizing a group of evolutionarily conserved proteins called the heat-shock proteins (HSPs) that, by acting as molecular chaperones, protect the cell against the aggregation of denatured proteins and play a significant role in adaptation to temperature. The present study aimed to investigate the critical thermal maxima (CTMax) and the expression of HSP70 in different tissues (gill, brain, muscle and liver) of an endemic catfish Horabagrus brachysoma acclimated at either 20 or 30°C for 30?days. To understand the HSP70 response, fish acclimated to the two temperatures were exposed to preset temperatures (26, 30, 34, 36 and 38°C for 20°C acclimated fish and 32, 34, 36, 38 and 40°C for 30°C acclimated fish) for 2?h, followed by 1?h recovery at their respective acclimation temperatures. The HSP70 levels in the gill, brain, muscle and liver tissues were determined by Western blotting of one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis. A significant (P?相似文献   

14.
黑鲷幼鱼饲料蛋白源氨基酸平衡的研究   总被引：13，自引：1，他引：12  
以黑鲷幼鱼肌肉的氨基酸组成作为幼鱼饲料中必需氨基酸需要量的标准模式,通过必须氨基酸指数（ＥＡＡＩ）和生物饲养试验结果相结合,对黑钱财幼鱼的９种不同蛋白源酸比的饲料进行了比较研究,对黑钱财幼鱼配合饲料中氨基酸平衡和蛋白质营养价值进行了评估,筛选出个高效饲料蛋白源配方;表明ＥＡＡＩ是鱼用饲料蛋白质营养价值评估和氨基酸平衡研究的一种简便有效的评价指标。  相似文献   

15.
Juvenile gilthead sea bream (initial body weight ca. 100 g) were reared in an indoor flow through marine water system for 1 year. Fish were fed two isoenergetic [19.2 kJ g−1 dry matter (DM)] and isoproteic (426 g kg−1 DM) diets either based on fish meal (diet FM) or on a mixture of plant protein sources (diet PP), replacing 75% of fish meal protein. The growth trial was conducted in duplicate, two tanks for each dietary treatment. Growth performance and feed utilization were registered. Fillet quality parameters were evaluated and sensory analyses on cooked fillet were performed. Both groups had similar weight gain and specific growth rates. Feed intake was higher in sea bream fed diet FM (0.48 versus 0.44), while feed efficiency and protein efficiency ratio were significantly higher in sea bream fed PP (0.83 versus 0.77 and 2.0 versus 1.76, respectively). Sea bream fed diet FM had a lower hepatosomatic index (0.80 versus 0.87%), and a higher fillet yield (45.9 versus 44.9%). The fillet from sea bream fed diet FM had higher moisture (696 versus 682 g kg−1), lower lipid levels (91 versus 100 g kg−1) with higher levels of n‐3 polyunsaturated fatty acids (PUFA) and monounsaturated fatty acids (MUFA), while the PP fed sea bream presented a higher level of PUFA n‐6. There were minor differences in muscle free amino acid levels between the two diet groups. As regards sensory evaluation of cooked fillet, the judges were unable to discriminate the two dietary groups of fish. Summarizing, the results demonstrate the possibility to use diets containing high levels (750 g kg−1) of plant ingredients in gilthead sea bream without affecting growth performance and with minor effects on quality traits of commercial size sea bream.  相似文献   

16.
To establish the practical use of microbound diets (MBD) for larval fish in mass seedling production, rearing experiments of larval red sea bream, Pagrus major , and Japanese flounder, Paralichthys olivaeeus , were conducted. A mixture of various protein sources was used, and dietary amino acid patterns were approximated to those of larval whole body protein. Two thousand red sea bream larvae and 1,000 Japanese flounder larvae, all 10 days old, were placed in 100 liter tanks with running sea water under ambient water temperature, which ranged from 18 to 20C. The particle size of MBD was 125 μm at the beginning of the experiment and adjusted as fish size increased thereafter. Employing MBD together with a small amount of live food could sustain the growth and survival of larval red sea bream and Japanese flounder. Thus, data from the present study indicates that substitution of artificial feeds for live foods is possible for larval fish production, although improvements in MBD diets may be necessary before they are adequate for large scale seedling production.  相似文献   

17.
SUMMARY: The aim of this study was to investigate the cause of green liver in red sea bream fed substitute protein diets. Red sea bream Pagrus major was given either of the following diets for 28 weeks: (1) control diet (50% fish meal), (2) low level fish meal diet (15% fish meal), and (3) non-fish meal diet (0% fish meal). The green liver was observed in all groups tested, but the incidence was much higher in the experimental diet groups. The feeding of substitute protein diets reduced plasma triglyceride and cholesterol levels. However, there was no significant difference in plasma hepatic enzyme activities and plasma bile salts concentration among the treatments. Fish fed the substitute protein diets showed low hepatic taurine levels with an appearance of a biliverdin in the liver. Moreover, the proportion of ditaurobilirubin to total biliary bile pigments was significantly lower in fish fed the substitute protein diets. These data indicate that feeding of substitute protein diets did not induce any cholestatic hepatobiliary obstructions and that the low hepatic taurine level was one of the probable factors responsible for the occurrence of green liver in red sea bream fed substitute protein diets.  相似文献   

18.
Low temperatures, and the voluntary fasting that they induce, have been implicated in outbreaks of winter syndrome in farmed gilthead sea bream (Sparus aurata). Two experiments were performed with the objective of studying if a decrease in water temperature is sufficient to induce this disease or some of its associated signs. In the first experiment, water temperature was either acutely or gradually reduced to 8 °C. In the second experiment, fish were exposed to either 8 °C or 12 °C, or fasted at 14 °C. Although no mortalities due to winter syndrome were registered during any of the experiments, some of the signs described in affected sea bream were observed in 8 °C-exposed fish. Among the most relevant were the paleness and friability of the liver and the occurrence of fatty degeneration in the hepatocytes. During the experiments, the general state of health of fish was monitored by measuring hematic parameters and the plasma concentration of proteins, glucose and ions. Low temperatures (8 and 12 °C) and fasting at 14 °C resulted in significant decreases in the levels of the different plasma protein fractions. This drop was more important in all the 8 °C-exposed fish, due mainly to a higher descent of albumin, α1-globulins and fibrinogen. Moreover, 8 °C-exposed fish showed a fall in total white blood cells and a rise of plasma glycemia, as well as a significant drop of plasma potassium and calcium levels and a transient increase of plasma magnesium concentration. In 8 °C-exposed fish, the rate of water temperature descent did not modify the profiles of change of any of the studied parameters. These results indicate that at 8 °C gilthead sea bream are unable to maintain the levels of plasma protein fractions and ions present in control animals. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

19.
ABSTRACT:   Predation experiments were conducted in mesocosms to test the hypothesis that habitat complexity affects vulnerability of red sea bream Pagrus major juveniles to piscivorous fish predators. Juvenile behavior was video-recorded for 6 h in two structurally different habitats: vegetated with sea grass Zostera marina , and unvegetated 0.5-t tanks. Association behavior with seagrass was observed in the vegetated tank throughout the trials. Predation experiments were conducted with 30 red sea bream juveniles (29.9 mm body length) exposed to two individuals of the piscivorous fish predator Chinese sea bass Lateolabrax sp. (261.6 mm), for 6 h in 1.0-t tanks. Predation rate (no. of fish predated on per predator per h) was significantly lower in the vegetated tank (0.02/predator per h) than in the unvegetated tank (0.27/predator per h). Present experiments indicate that habitat complexity reduces vulnerability of juvenile red sea bream to predation by piscivorous fish by serving as physical and/or visual barriers and limiting the predator's ability to pursue and capture prey. Seagrass beds in the shallow coastal waters around Japan are suggested to be an important nursery for red sea bream since they provide the juveniles with habitat complexity as well as serve as a feeding ground.  相似文献   

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