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1.
Expression of taurine transporter in response to osmotic stress was investigated at the protein level in the mantle of the Mediterranean blue mussel by using the specific antibody raised against the carboxy-terminal region of the deduced amino acid sequence of mussel taurine transporter. Immunohistochemical observation revealed that taurine transporter was expressed in the mantle and the expression was up-regulated in response to hypo-osmotic stress, while down-regulated in response to hyper-osmotic stress. Western blot analysis revealed major protein bands corresponding to 62 kDa and 65 kDa. In response to hypo-osmotic stress, the 62 kDa band became more intense, while it became less intense when the ambient osmolality was elevated. These results suggested that the 62 kDa taurine transporter would be implicated in hypo-osmotic adaptation.  相似文献   

2.
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3.
ABSTRACT:   The effects of dietary taurine levels and lipid contents on the conjugated bile acid composition and growth performance of juvenile Japanese flounder Paralichthys olivaceus were investigated. Six types of diet (three different levels of taurine at two different levels of lipid) were fed to juveniles (average body weight, 0.04 g). Fishmeal that was washed with 70% ethanol to remove taurine was used as the sole protein source. Feeding experiments were carried out at 20°C for 6 weeks. At the end of the experiments, fish were weighed and analyzed for free amino acids in the body and the composition of the conjugated bile acids. The body weight and percent weight gain of the juveniles were improved by the dietary taurine supplementation. The taurine contents of the whole body and tissues increased with the increase of the dietary taurine contents. The conjugated bile acids in the gall bladder consisted of taurocholic acid and taurochenodeoxycholic acid, which increased with the increase of the dietary taurine level. Taurocholic acid accounted for more than 95% of the total conjugated bile acids. This indicates that taurine is the sole amino acid to conjugate bile acid in Japanese flounder.  相似文献   

4.
The effect of graded levels of dietary taurine on growth, enzyme activities and pretrypsinogen (Ptry) mRNA expression in the tongue sole postlarvae was evaluated in this study. Four microdiets supplemented with 0 (T0), 5 (T0.5), 10 (T1.0) or 20 (T2.0) g kg?1 taurine were prepared. These diets were fed to the postlarvae with an average initial body dry weight of 3.32 ± 0.06 mg for 28 days. Survival and growth performance of the tongue sole postlarvae were significantly (P < 0.05) influenced by dietary taurine. Survival rate of fish fed with 20 g kg?1 dietary taurine was significantly lower than other treatments. The growth of fish initially increased with increasing dietary taurine level and then decreased. Postlarvae fed with 10 g kg?1 dietary taurine showed the best growth performance. Trypsin activities showed a significant increase with increasing dietary taurine level and then reached a plateau, while amylase activities and alkaline phosphatase activities increased in the start with increasing dietary taurine and then decreased. Ptry mRNA expression was stimulated by dietary taurine. Excessive dietary taurine (20 g kg?1) had adverse effects on survival, growth, digestive enzyme activities of the experimental fish. The suggested dietary taurine supplementation in microbound diets was 10 g kg?1 for the tongue sole postlarvae.  相似文献   

5.
ABSTRACT:   The physiology of yellowtail fed a non-fishmeal diet was examined, with a specific interest in the role of taurine in disease resistance and cholesterol metabolism. Decrease of disease resistance in fish fed a non-fishmeal diet was confirmed by mortality due to natural infection with pseudotuberculosis and artificial infection with Lactococcus garvieae . It is suggested that the most important symptoms related to decrease of disease resistance in fish fed a non-fishmeal diet is anemia. Anemia was improved by supplementation with taurine. Significant elevation of relative expression of HMG-CoA reductase mRNA in fish fed a non-fishmeal diet suggests that cholesterol synthesis would be activated and not dysfunctional. Plasma cholesterol of these fish was elevated to the levels of control fish by supplementation of both cholesterol and taurine. These results suggest that hypocholesterolemia observed in fish fed a non-fishmeal diet compared with a fishmeal diet would be caused by insufficient dietary cholesterol and decrease of endogenous cholesterol due to the lack of dietary taurine.  相似文献   

6.
ABSTRACT:   The effect of taurine on growth of yellowtail juveniles Seriola quinqueradiata was investigated by a feeding experiment of diets containing various taurine levels. Test diets supplemented with 0, 0.5, 1.0, 1.5 and 2.0% of taurine were prepared. These diets were fed to yellowtail juveniles with an initial mean body weight of 0.5 g for 6 weeks. Supplementation of taurine in the diet of yellowtail improved their growth performance significantly ( P  < 0.05) over the initial 3-week period. The fish fed with the taurine-supplemented diet improved in percent gain and feed efficiency over both 3 and 6 weeks. Taurine content in the muscle proportionally increased with the dietary taurine level. The fish fed without supplemented taurine diet showed higher contents of serine in the muscle. With each increase in the inclusion level of taurine content in the diet, the concentration of serine in the muscle decreased. The cystathionine content in the muscle of each group was unchanged. These results suggest that taurine supplementation in the diet not only improves growth but also affects the sulfur amino acid metabolism of yellowtail juveniles.  相似文献   

7.
ABSTRACT:   The effect of dietary taurine on juvenile Japanese flounder was determined by feeding three taurine-supplemented experimental diets (TAU) and a commercial diet (CD) to evaluate a practical diet for juvenile Japanese flounder. Juvenile Japanese flounder were reared on the three experimental diets supplemented with taurine at 0, 0.5, 1.0% and CD. These diets were fed to juvenile Japanese flounder of an initial mean body weight of 0.2 g for 6 weeks at 20°C and the taurine contents of the whole body and tissues were analyzed. The final average body weight of juvenile Japanese flounder fed the 1.0% TAU was significantly higher than that of the other groups. Taurine contents in the whole body and tissues increased with the increase in dietary taurine level. These results indicate that juvenile Japanese flounder require at least 15 mg/g taurine in the diet, even though a combined mix of fish, krill and squid meal was the main protein source in the experimental diets.  相似文献   

8.
Seawater around deep-sea hydrothermal vents and cold seeps contain high levels of hydrogen sulfide, which is toxic to most animals. Invertebrates inhabiting these environments have been reported to accumulate high levels of thiotaurine, a sulfur-containing amino acid. Thiotaurine is likely to play an important role in sulfide detoxification, but its functions in the detoxification process are still unknown. We cloned methane-seep mussel Bathymodiolus platifrons cDNA encoding the taurine transporter (TAUT), which transports thiotaurine and its precursors across the cell membrane. Phylogenetic analyses revealed that the predicted peptide formed a clade with the TAUTs of shallow-water mussel Mytilus galloprovincialis and the hydrothermal vent mussel Bathymodiolus septemdierum that harbors thioautotrophic bacteria. We then reared B. platifrons in the presence or absence of Na2S and quantified TAUT mRNA using a real-time PCR system. The amount of TAUT mRNA in the gills of B. platifrons increased with rearing in the presence of Na2S for 69 days, but no change was observed in the absence of sulfide. These results suggest that TAUT plays an important role in sulfide detoxification, even in species that do not harbor thioautotrophic bacteria. The TAUT mRNA level was variable in the mantle and low in the foot throughout the entire rearing period, regardless of the presence/absence of sulfide, suggesting that TAUT gene expression is regulated differentially in each tissue.  相似文献   

9.
为探讨饲料牛磺酸含量对斜带石斑鱼幼鱼生长性能、体成分、TauT mRNA表达量及牛磺酸合成关键酶(CSD和CDO)活性的影响,实验在以酪蛋白和明胶为蛋白源的基础饲料(0DT)中分别添加0.5%(0.5DT)、1.0%(1.0DT)、1.5%(1.5DT)的牛磺酸,配制成4种不同牛磺酸含量的饲料。将平均体质量为(13.85±0.25) g的320尾斜带石斑鱼幼鱼随机分为4组,每组4个循环水族箱,每箱放养20尾鱼,每组分别投喂一种相同实验饲料,每天定时投喂实验饲料至表观饱食状态,实验为期84 d。结果显示,在0DT饲料中补充外源牛磺酸能显著提高饲料效率、摄食率、增重率和全鱼粗蛋白含量,而显著降低肝体比和全鱼粗脂肪含量。组织中肝脏、肌肉、肠道TauT mRNA表达量在1.0DT组时达到最大值,且显著高于其他各组,当饲料牛磺酸含量继续增加至1.5DT组时明显降低,但仍显著高于0DT和1.0DT组。斜带石斑鱼幼鱼血浆、肝脏、肠道和肌肉中牛磺酸含量与饲料牛磺酸含量之间呈正相关。饲料中补充外源牛磺酸能够显著降低肝脏、肌肉中CSD活性,同时降低血浆、肝脏、肠道和肌肉中CDO活性,但对血浆CSD活性无显著影响。研究表明,饲料中补充外源牛磺酸能够明显促进斜带石斑鱼幼鱼生长,增加鱼体蛋白沉积,同时降低鱼体脂肪沉积,上调组织中TauT mRNA表达水平及提高牛磺酸蓄积,降低牛磺酸合成关键酶活性。研究表明,以增重率为目标,通过二次多项式回归分析,饲料中牛磺酸的适宜含量为0.92%。  相似文献   

10.
This study describes the effects of feeding taurine‐supplemented Artemia on the growth, survival, whole body taurine content and jaw malformation rate of larval yellowtail kingfish Seriola lalandi. Larvae were fed rotifers containing no supplemental taurine from 3 to 15 day post hatch (dph) and Artemia co‐enriched with taurine from 12 to 22 dph. Artemia were supplemented at concentrations of either 0, 0.8, 1.6, 2.4, 3.2 or 4.0 g of taurine L?1 during the 18 h HUFA enrichment process. Taurine content in the Artemia increased from 0.76 ± 0.04% DW in those without supplementation to 3.95 ± 0.17% DW in those supplemented at 4.0 g L?1. Survival rates of larval yellowtail kingfish were significantly lower in all taurine‐supplemented treatments compared to the unsupplemented control. Growth was significantly improved in those larvae fed taurine‐supplemented Artemia; however, we cannot attribute this improvement solely to taurine, as improved growth may have been a function of the reduced survival, and therefore increased prey availability, in these treatments. The whole body taurine content of larvae fed unsupplemented Artemia was significantly lower (1.85 ± 0.03% DW) than those fed supplemented Artemia, which did not differ from each other (pooled average 2.48 ± 0.03% DW), suggesting either a functional excretion mechanism is in place or that this represents the saturation value for larvae of this age. Jaw malformation rates were not affected by Artemia taurine content. The results of this research suggest yellowtail kingfish larvae may have a lower requirement and/or a reduced tolerance to excess dietary taurine than juveniles.  相似文献   

11.
This study was conducted to evaluate the effects of dietary taurine on growth performance and feed utilization of Nile tilapia (Oreochromis niloticus) larvae. Four plant protein‐based, isonitrogenous (400 g kg?1 protein), isoenergetic (19 MJ kg?1) diets supplemented with four taurine concentrations (0.0, 5.0, 10.0 and 15.0 g kg?1; designated as T0, T0.5, T1 and T1.5, respectively) were prepared. The diets were fed to triplicate groups of fish larvae (0.024 g average body weight), to apparent satiation, three times per day for 60 days. Larval growth rates and feed utilization efficiency were significantly improved with increasing supplemental taurine up to 10 g kg?1 and decreased with further taurine supplementation. The quadratic regression analyses indicated that the maximum larval performance occurred at about 9.7 g kg?1 of total dietary taurine. Fish survival was significantly lower at 15 g kg?1 dietary taurine than at other taurine levels. Body protein significantly increased, while body moisture and ash decreased, with increasing dietary taurine up to 10 g kg?1 and decreased with further taurine supplementation to 15 g kg?1. Body lipid was not significantly affected by dietary taurine concentration. A number of body amino acids (tryptophan, arginine, histidine, leucine, isoleucine, valine, alanine, glycine, threonine and taurine) significantly increased with increasing supplemental taurine up to 10 g kg?1 and then decreased with further increase in dietary taurine levels. The rest of body amino acids were not significantly affected by dietary taurine. The present results suggest that about 9.7 g kg?1 dietary taurine is required for optimum performance of Nile tilapia larvae fed soybean meal‐based diets.  相似文献   

12.
This study determined the effect of dietary supplementation with taurine on plasma biochemical indices, blood cell apoptosis rate, survival rate and expression of catalase (CAT), glutathione reductase (GR) and heat‐shock protein 70 (HSP70) gene in juvenile hybrid snakehead under ammonia stress. Six diets were formulated to contain 0, 3.0, 6.0, 9.0, 12.0 and 15.0 g/kg taurine. Each diet was fed to triplicate groups of fish in cylindrical tanks. After 8 weeks of feeding, 20 fish per tank were exposed to ammonia stress (total ammonia nitrogen = 200 mg/L) for 48 hr. The results showed that, after ammonia stress, plasma alkaline phosphatase (ALP), triacylglycerol (TG) levels and survival rate significantly decreased (p < 0.05) while plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea nitrogen (BUN), respiratory burst, blood cell apoptosis rate, hepatic CAT, GR and HSP70 mRNA expression levels significantly increased (p < 0.05). On the other hand, dietary supplementation with taurine significantly reduced levels of BUN, respiratory burst and blood cell apoptosis rate. Supplemented groups significantly increased relative mRNA expression of hepatic CAT, GR and HSP70 as well as increased survival rate (p < 0.05). These results indicated that dietary supplementation with taurine improved ability to resist ammonia stress in hybrid snakehead.  相似文献   

13.
An 8‐week feeding trial was conducted to investigate the effects of different taurine levels on the growth performance of juvenile white shrimp fed with low‐fishmeal diets. Six level diets of dietary taurine were prepared by the supplementation of taurine (0, 0.4 g kg?1, 0.8 g kg?1, 1.2 g kg?1, 2.0 g kg?1 and 4.0 g kg?1) to a control diet (100 g kg?1 fish meal). Each diet was randomly assigned to triplicate groups of 30 shrimps (0.48 ± 0.0 g), each three times daily. Shrimp fed the 0.4 g kg?1 and 0.8 g kg?1 taurine‐supplemented diets, showed significantly higher weight gain, protein efficiency ratio and protein retention efficiency than those of shrimp fed the other diets. The quadratic regression analysis (y = ?55.59x2 + 187.1x + 750.2 R² = 0.587) indicated that a maximum weight gain occurring at 1.68 g kg?1 of taurine level. The whole body and hepatopancreas taurine contents of the taurine‐supplemented diets were on the same level and higher than those of the control group. Total free amino acid content in the hepatopancreas was significantly affected by taurine supplementation. The results of the present study demonstrate that the white shrimps require taurine as an essential nutrient for growth performance.  相似文献   

14.
Leaching of soluble compounds from pelleted feeds is an issue for the aquaculture industry through increased environmental impact and reduced ingestion essential components. This study was undertaken to examine the leaching rates of taurine, a non‐protein amino acid with critical physiological roles in teleosts. To this end we adapted a new liquid chromatography mass spectrometry (LC‐MS) method for quantifying taurine. Twelve different feeds (4 mm dia.) varying in protein source and taurine levels were examined. Fishmeal content ranged from 0.0% to 45.5% with taurine supplementation ranging from 0.0% to 5.0%. Taurine was extracted and quantified from individual pellets in triplicate at six time points (0, 1, 5, 10, 20 and 40 min). Leaching rates ranged from 0.026 ± 0.005 to 0.826 ± 0.121 mg min?1 over 40 min at 27°C and were strongly correlated to initial taurine content of the feeds (for distilled water n = 12, P < 0.001, R2 = 0.91 for artificial seawater, 25 ppt, n = 4, P = 0.020, R2 = 0.96). Loss of taurine from feeds was 59.5 ± 16.5% after 40 min. This study shows that a significant amount of taurine is lost over time from uneaten feed and that taurine supplementation should exceed requirement levels for slow consumers or feed being delivered as multiple additions.  相似文献   

15.
ABSTRACT:   Three diets supplemented with taurine, β-alanine andGABA and a control diet were fed to juvenile and fingerling Japaneseflounder to investigate the effects of the diets on growth and metabolicchanges of free amino acids in whole body and tissues. In experimentI, three diets supplemented with 1% each of taurine, β-alanineand GABA and a control diet were fed to juvenile Japanese flounderwith an initial mean body weight of 0.4 g for 4 weeks at20°C. In experiment II, the taurine-supplemented diet anda control diet were fed to fingerling Japanese flounder with an initialmean body weight of 15 g for 4 weeks at 20°C.Only supplementation of taurine in the diet of juvenile flounderimproved their growth performance in experiment I, but fingerlinggrowth performance of experiment II was not significantly relatedto taurine supplementation in the experimental diet. These resultssuggest that there is a greater requirement for taurine for thegrowth of juvenile Japanese flounder than fingerling Japanese flounder.  相似文献   

16.
This study was conducted to evaluate the effects of supplemental taurine on reproductive performance of Nile tilapia (Oreochromis niloticus) broodstock fed soybean meal‐based diets. Four isonitrogenous (350 g kg?1 protein), isocaloric (18 MJ kg?1) diets were formulated to contain 0, 5, 10 and 15 g kg?1 taurine. The diets were fed to triplicate groups of juvenile Nile tilapia (10–15 g average body weight) at a female: male ratio of 3 : 1, to apparent satiation, three times per day for 130 days. The size at first maturation decreased with increasing dietary taurine to 10 g kg?1 and levelled off with further taurine supplementation. The time to first spawning was also significantly shorter at 10 g kg?1 taurine level. Spawning performances, including spawning frequencies, total number of spawnings per tank, number of spawnings per female and absolute fecundity, were all significantly improved with increasing dietary taurine up to 10 g kg?1. However, the quadratic regression analyses indicated that the maximum spawning performance occurred at 8 g kg?1 of supplemental taurine. Eggs produced from broodstock fed 10 g kg?1 taurine exhibited significantly higher hatchability and required shorter time for hatching and yolk‐sac absorption and also resulted in higher larval weight than at other dietary taurine levels. The highest egg protein, total amino acids and taurine were also obtained at 10 g kg?1 taurine. These results suggest that 8 g kg?1 dietary taurine is required for optimum reproductive outputs of Nile tilapia broodstock.  相似文献   

17.
ABSTRACT:   This study was performed to evaluate the efficacy of taurine supplementation for preventing green liver syndrome and improving growth performance in red sea bream Pagrus major fed a low-fishmeal (FM) diet. Yearling red sea bream were fed for 34 weeks on low-FM diets either supplemented with taurine, or without taurine, and the tissue taurine and bile pigment concentrations were measured. Compared to the fish fed the FM diet, fish fed the low-FM diet without taurine supplementation resulted in inferior feed performances and higher incidence of green liver related to the morphological transformation of the erythrocytes. In these fish, the hepatopancreatic taurine concentration was significantly lower and hepatopancreatic biliverdin concentration was high compared to the fish fed the FM diet. These parameters were markedly improved by taurine supplementation of the low-FM diet and were similar in levels to the fish fed the FM diet. These results indicate that green liver appearance and inferior feed performances of red sea bream fed the low-FM diet without taurine supplementation were caused by dietary taurine deficiency, and indicate the requirement of taurine supplementation to low-FM diets for red sea bream.  相似文献   

18.
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19.
This study was conducted to investigate the effects of different taurine levels on the conjugated bile acid composition and growth of juvenile rockfish. Five taurine level diets were made by the supplementation of taurine (0%, 0.5%, 1.0%, 1.5% and 2.0%) to a basal diet. Fish meal washed with 70% ethanol to exclude taurine was used for the sole protein source. Feeding experiments were accomplished at 15°C using juvenile fish (initial BW: 13.5 g). Fish were fed the experimental diets for 4 months. At the end of experiments, fish were weighed and stored at ?80°C for analysis of free amino acids and conjugated bile acids contents. The growth performance and feed efficiency of Korean rockfish were improved by taurine supplementation in the experimental diets. The taurine contents of the whole body increased with the increase in the taurine supplementation. The primary conjugated bile acids in gall bladder were taurocholic acid (83.5–165.6 mg mL?1) and taurochenodeoxycholic acid (6.3–20.0 mg mL?1). Total bile acids increased with increases in dietary taurine. Taurocholic acid content was more than 95% of the total conjugated bile acids. This indicates that taurine is the sole amino acid to make conjugated bile acid in Korean rockfish. Dietary taurine levels improved the conjugated bile acid composition in juvenile Korean rockfish.  相似文献   

20.
A feeding trial was conducted on the effects of methionine hydroxy analog (MHA) and taurine supplementation in diets with high levels of soy protein concentrate (SPC) on the growth performance and amino acid composition of rainbow trout, Oncorhynchus mykiss (Walbaum) comparing with fish meal based diet. The control diet had 520 g kg?1 fish meal. In the methionine deficient diets (5.1 g kg?1), fish meal was replaced by 490 g kg?1 of the SPC in the SPC49 diet. The SPC49 diet was supplemented with either MHA (6 g kg?1) only or a combination of MHA and taurine (2 g kg?1). Fish were fed isoproteic (460 g kg?1) and isolipidic (130 g kg?1) diets for 12 weeks. Growth performance (i.e. weight, feed conversion ratio, and thermal‐unit growth coefficient) was inferior in fish fed the SPC49 diet. MHA supplementation improved growth performance (P < 0.05). No difference was observed when taurine was added to the SPC49 and MHA diet (P > 0.05). Whole‐body taurine contents increased with taurine supplementation, whereas plasma methionine increased with MHA supplementation (P < 0.05). In conclusion, the substitution of fish meal with SPC supplemented with MHA did not negatively impact growth, and the addition of taurine did not improve growth performance in rainbow trout.  相似文献   

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