The aquaculture industry has developed significantly over the past few decades and has had a substantial impact on the global food supply and marine fisheries resources.However,some problems arise behind the scenes du...The aquaculture industry has developed significantly over the past few decades and has had a substantial impact on the global food supply and marine fisheries resources.However,some problems arise behind the scenes due to excessive intensive farming,such as slow animal growth,frequent disease,and lipid metabolism disorders.These problems have limited the sustainable development of the aquaculture industry,and a continuable solution is required.The use of fungal polysaccharide appears to provide a solution to these problems.Therefore,different supplemented levels of Poria cocos polysaccharide(PCP)(0,0.4,0.8,1.2,1.6,and 2.0 g/kg,respectively)were fed to spotted sea bass(Lateolabrax maculatus)in similar size(30.28±0.18 g)in current study.The effects of PCP on growth,physiological parameters,and lipid metabolism of spotted sea bass were investigated after a 4-week rearing period.Results showed,fish with PCP intake presented a significantly higher weight gain,specific growth rate,and a significantly lower feed conversion ratio.Significantly higher trypsin activity in liver and intestine were observed in fish with PCP intake.The superoxide dismutase activity in serum and liver of fish with PCP intake were significantly improved,while significantly higher serum total antioxidant capacity and hepatic catalase activity were also observed.However,no significant differences in lysozyme and alkaline phosphatase activity were evident among groups.Fish with PCP intake showed a significantly lower total cholesterol,but no noteworthy change in triglyceride and lipid-metabolismrelated genes expression were observed among groups.Results indicated that intake of PCP has a positive effect on growth and antioxidant capacity of spotted sea bass,but seems to have a limited effect on the non-specific immunity and lipid metabolism of spotted sea bass.Based on the regression analysis results,1.4 g/kg of PCP is the optimal dose for spotted sea bass in size(30.28±0.18 g).展开更多
The caspase gene family is a crucial gene cluster that regulates apoptosis which contribute to programmed cell death,cell proliferation and differentiation,and several immune responses.In our study,a complete set of 1...The caspase gene family is a crucial gene cluster that regulates apoptosis which contribute to programmed cell death,cell proliferation and differentiation,and several immune responses.In our study,a complete set of 12 caspase genes were identified in spotted sea bass Lateolabrax maculatus.These genes were divided into three subfamilies:2 inflammatory caspases(casp-1 and casp-14-like),5 apoptosis initiators(casp-2,casp-8a,casp-8b,casp-9,and casp-10),and 5 apoptosis executioners(casp-3a,casp-3b,casp-3-like,casp-6,and casp-7).Their phylogenetic relationships,synteny and gene structures were systematically analyzed.Furthermore,the relative expression profiles of the caspase family members in the liver,intestine,head kidney,and spleen were measured by q PCR after infection with Vibrio harveyi.The results showed that the overall mRNA levels of the caspase genes were dramatically increased after V.harveyi infection,and the expression patterns varied among genes and tissues.More caspase genes underwent pronounced expression changes in the head kidney and spleen than in the liver or intestine,mainly after 48 h of the challenge.Specifically,casp-3a,casp-3b,casp-3-like,casp-6,casp-7,casp-8a,casp-8b,casp-10,and casp-14-like in the head kidney,and casp-3-like,casp-6,casp-7,and casp-14-like in the spleen,were the most responsive caspase genes which may contribute significantly to immune regulation in spotted sea bass.Additionally,the apoptosis level in head kidney and spleen after infection were examined using the Caspase assay.Our study provides a systemic overview of the caspase gene family in spotted sea bass after V.harveyi infection and lays a foundation for further deciphering the biological roles of these caspase genes.展开更多
D-dopachrome tautomerase(DDT),a member of the macrophage migration inhibitory factor(MIF)protein superfamily,is a newly described cytokine with chemokine-like characteristics.However,research on fish DDT remains limit...D-dopachrome tautomerase(DDT),a member of the macrophage migration inhibitory factor(MIF)protein superfamily,is a newly described cytokine with chemokine-like characteristics.However,research on fish DDT remains limited.In this study,we identified a DDT homolog(LjDDT)from the Japanese sea bass,Lateolabrax japonicus.Sequence analysis showed that LjDDT had typical sequence features of known DDT and MIF homologs and was most closely related to DDT of rock bream(Oplegnathus fasciatus).LjDDT transcripts were detected in all tested tissues of healthy Japanese sea bass,with the highest expression found in the liver.Upon infection with Vibrio harveyi,LjDDT transcripts were significantly down-regulated in the three tested tissues,including the liver,spleen,and head kidney.Recombinant LjDDT(rLjDDT)and the corresponding antibody(anti-rLjDDT)were subsequently prepared.The administration of 100μg/g anti-rLjDDT had a statistically significant protective effect on the survival of V.harveyi-infected fish.Moreover,rLjDDT was able to induce the migration of monocytes/macrophages(MO/MФ)and lymphocytes both in vitro and in vivo,but without significant influence on the migration of neutrophils.rLjDDT exhibited chemotactic activity for lipopolysaccharide(LPS)-stimulated M1-type MO/MΦin vitro,but not for cAMP-stimulated M2-type MO/MΦ.Furthermore,the knockdown of LjCD74,but not LjCXCR4,significantly down-regulated the rLjDDT-enhanced migration of MO/MΦand relieved the rLjMIF-inhibited migration of MO/MΦ.These results indicate that LjCD74 may be the major chemotactic receptor of LjDDT and LjMIF in Japanese sea bass MO/MΦ.Combined rLjDDT+rLjMIF treatment had no significant effect on the migration of MsiRNA,LjCD74si-,or LjCXCR4sitreated MO/MΦcompared to the control group,suggesting that the roles of LjDDT and LjMIF may be antagonistic.In conclusion,our study demonstrates for the first time that DDT may play a role in the immune responses of fish against bacterial infection through chemotactic recruitment of MO/MΦvia mediation of CD74 as an antagonist of MIF.展开更多
The RNA helicase Vasa is an important regulator of primordial germ cell development. Its function in mature fish, espe- cially the hormone-related differences in maturing male fish has seldom been documented. In this ...The RNA helicase Vasa is an important regulator of primordial germ cell development. Its function in mature fish, espe- cially the hormone-related differences in maturing male fish has seldom been documented. In this study, a full length cDNA sequence of the vasa gene was cloned from Japanese sea bass, Lateolabraxjaponicas, and it was namedjsb-vasa. Homology analysis showed thatjsb-vasa was closely related to its teleost homologs. The spatial distribution ofjsb-vasa indicated that it was only highly ex- pressed in testis, showing its germ cell-specific expression pattern. During the testicular development cycle, jsb-vasa was highly expressed during early period of spermatogenesis, and reduced when spermatogenesis advanced. In addition, the jsb-vasa gene ex- pression was significantly inhibited at 6 h, 12 h and 24 h after injecting hCG （human ehorionic gonadotropin） and GnRHa （Gonad- otropin-releasing hormone analogue）, indicating thatjsb-vasa gene may play an important role in spermatogenesis of Japanese sea bass, and be under the regulation of external sex hormones.展开更多
Previous studies have shown the existence of a complement system in the amphioxus Branchiostoma japonicum.How-ever,whether it has an opsonic activity similar to that of vertebrates remains unknown.We demonstrated that...Previous studies have shown the existence of a complement system in the amphioxus Branchiostoma japonicum.How-ever,whether it has an opsonic activity similar to that of vertebrates remains unknown.We demonstrated that the humoral fluid(HF)of amphioxus promoted the phagocytosis of yeast cells with sea bass(Lateolabrax japonicus)macrophages,whereas the C3-depleted and heated HF significantly lost the phagocytosis-promoting capacity.In addition,the precipitation of factor B(Bf)led to a marked loss of opsonic activity.Moreover,C3 fragments in the HF were found to bind to yeast cell surfaces.The results indicate that the amphioxus complement system is an important element involved in the opsonic activity,which promotes the sea bass macrophage phagocytosis by tagging yeast cells with C3 fragments via the activation of alternative complement pathway.展开更多
In this study, trace metals [Cadmium (Cd), Mercury (Hg) and Lead (Pb)] consentration of 76 pieces of frozen European sea bass (Dicentrarchus labrax Linnaeus-1758) and gilthead sea bream (Sparus aurata Linnaeus-1758) f...In this study, trace metals [Cadmium (Cd), Mercury (Hg) and Lead (Pb)] consentration of 76 pieces of frozen European sea bass (Dicentrarchus labrax Linnaeus-1758) and gilthead sea bream (Sparus aurata Linnaeus-1758) fillets, produced and marketed in Turkey, were determined using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) after microwave damp burning process, and results obtained were assessed in terms of public health. This study was conducted from June 2010 to July 2011. At the end of study, maximum heavy metal levels for sea bass and sea bream fillets were determined as 256.50, 216.22 μg/kg for Cd;414.79, 338.46 μg/kg for Hg ve 1047.61, 147.14 μg/kg for Pb, respectively. At the end of the study, the levels of cadmium (for 3 samples) and lead (for 1 samples) were higher than the recommended legal limits of the European Union for human consumption. It was detected that the fillets which were analyzed was good quality from the point of cadmium, mercury and lead contents.展开更多
The effect of chitosan incorporated into feed formulation on the growth, feed utilization, body composition and histological response of sea bass (Dicentrarchus labrax) was investigated. Final fish weight, feed conver...The effect of chitosan incorporated into feed formulation on the growth, feed utilization, body composition and histological response of sea bass (Dicentrarchus labrax) was investigated. Final fish weight, feed conversion ratio (FCR), specific growth rate (SGR), protein efficiency ratio (PER), protein productive value (PPV), and energy utilization (EU) of sea bass feed chitosan supplemented diet and the control diet were determined at the end of experiment. Data presents mean ± SD from triplicate determination (n = 3) for 75 days feeding trial. Different concentrations (0.5, 1.0, 2.0, 3.0 & 4.0) and control without chitosan incorporated with total fish feed in the form of dry diets were fed for 75 days. Average final weight (FW) was significantly higher at diet 3 (1 g?kg?1 chitosan) and the lowest in control fish group, specific growth rate (SGR) was significant at diet 3. Also, protein efficiency ratio (PER), protein productive value (PPV), and energy utilization (EU) showed the same trend. The chemical body composition, crude protein, dry matter, crude fat and ash were significant (P ≤ 0.01) different compared to control groups. The present investigation suggested that the chitosan incorporated into diets of sea bass fish certainly enhanced the non specific responses and reduced mortality and also improved the growth performance of fish.展开更多
The effects of dietary garlic (Allium sativum) powder as a feed additive on hematological and biochemical health characteristics of European Sea bass Dicentrarchus labrax juveniles were studied. Experimental fish were...The effects of dietary garlic (Allium sativum) powder as a feed additive on hematological and biochemical health characteristics of European Sea bass Dicentrarchus labrax juveniles were studied. Experimental fish were fed diets supplemented with garlic powder at 0 (control), 2%, 4%, or 6% levels for a period of 60 days. Results showed that the red blood cell count (RBC), hemoglobin (Hb) concentration, hematocrit (%), and mean corpuscular Hb in fish fed garlic powder diets at dietary inclusion levels of 4% and 6%, were significantly lower than the control values. Serum glucose was significantly lower in Sea bass that were fed garlic powder diets (4% and 6%) compared to the control group. Serum triglyceride and globulin levels in fish fed a 4% garlic powder diet were significantly higher than the control values, whereas these two variables in the 2% and 6% garlic treatments were similar to the control values. The cholesterol levels in the 2% and 6% treatment groups were lower than the value recorded for the control group. As a result, it is suggested that garlic powder supplementation in diets for Sea bass juveniles should not exceed 2%. The present study is the first attempt to examine the effects of dietary garlic powder on the hematological and biochemical status in Sea bass juveniles.展开更多
This review summarizes the current knowledge on immune defence activities of the European sea bass Dicentrarchus labrax by reporting the consistent amount of work done on this economically-important species.A draft ge...This review summarizes the current knowledge on immune defence activities of the European sea bass Dicentrarchus labrax by reporting the consistent amount of work done on this economically-important species.A draft genome sequence is available for this species,together with whole transcriptomes from lymphoid and non-lymphoid tissues.Available full-length coding sequences of many immunoregulatory and immune-related genes allow for targeted quantitative PCR analysis,nowadays needed for-omics data verification,ex vivo and in vitro.The first anti-T cells monoclonal antibody teleost-wise was obtained in sea bass,followed by several monoclonal and polyclonal markers of lymphocyte populations,namely T cells(pan-T,CD3ε,TcRγ,CD45),and B cells(IgM,IgT,IgD).The combined use of molecular and biochemical tools enabled investigations on innate and acquired immune responses of sea bass in unstimulated/stimulated fish,along the development and under variable environmental conditions and food regimes.An overview of sea bass viral and bacterial pathogens and available vaccines against these microorganisms is also provided.The knowledge accumulated in the past 25 years validates the European sea bass as a reference marine model in the field of fish immunology.展开更多
This study was aimed at preparing chitosan(CS)-phenolic acids copolymers to obtain better preservation effect in marine products.In this work,CS was grafted onto phenolic acids such as gallic acid(GA)and protocatechui...This study was aimed at preparing chitosan(CS)-phenolic acids copolymers to obtain better preservation effect in marine products.In this work,CS was grafted onto phenolic acids such as gallic acid(GA)and protocatechuic acid(PA)by a carbodiimide coupling method.The copolymers(CS-grafted-GA(CS-g-GA)and CS-grafted-PA(CS-g-PA))were further confirmed through physicochemical properties including ultraviolet-visible(UV-Vis)spectrophotography,fourier transform infrared(FTIR)spectrometry,differential scanning calorimetry(DSC)thermogram,rheological behaviour,scanning electron microscope(SEM)and antioxidant activity analysis.Subsequently,the effects of copolymers on preservation of refrigerated sea bass(Lateolabrax japonicus)fillets were investigated.The results showed that the CS-g-GA(110.82 mg GA/g)exhibited higher grafting rate than CS-g-PA(62.63 mg PA/g).According to the assessment of UV-Vis and FTIR spectrometry,both the GA and PA were grafted onto CS successfully.SEM analysis demonstrated that the microstructure of copolymers became irregular.Meanwhile,both the CS-g-GA and CS-g-PA copolymers displayed superior thermal stability,rheological properties and antioxidant capacity than the pure CS.Furthermore,the copolymers also revealed a significantly stronger preservation effect on sea bass fillets including inhibiting microbial growth and delaying the deterioration of color,texture and sensory quality.Therefore,CS-g-GA and CS-g-PA could be used as promising preservatives for seafood.展开更多
Sea bass(Lateolabrax maculatus)is one of the important seafood in China.Its shelf-life under refrigerated storage exponentially deteriorate due to the growth of spoilage microorganisms,protein degradation and lipid ox...Sea bass(Lateolabrax maculatus)is one of the important seafood in China.Its shelf-life under refrigerated storage exponentially deteriorate due to the growth of spoilage microorganisms,protein degradation and lipid oxidation.In this study,4 coating materials namely,konjac glucomannan-whey protein isolate(KGM-WPI)film,chitosan-sweet potato starch(CHI-SPS)film,chitosan-bamboo fungus(CHI-BF)film,and chitosan-boehmite alumina(CHI-BAH)have been explored to enhance the shelf life of sea bass during 8 days of refrigerated storage.Overall,CHI-BF was observed to be best in retaining hardness,gumminess and maintaining total volatile basic nitrogen value.Whereas CHI-SPS was found to retain chewiness and maintain lower values for drip loss and peroxide value.CHI-BAH coating was observed to maintain the lower values for pH and EC values of sea bass under refrigerated storage.However,the least increase in total viable count and minimum change in b^(*)value was observed in the case of sea bass coated with KGM-WPI.The current research fi ndings provide a new practical storage method for the entire fresh fish.The fresh fish can be coated with different coating materials and store on the ice at 4℃without packaging during retailing.These film coated whole fresh fish retains its microbial and sensory quality.展开更多
Ghrelin(Ghrl),an appetite-inducing peptide hormone secreted by the stomach,is the endogenous ligand for the growth hormone secretagogue receptor(Ghs-r).In this study,we identified the preproghrelin gene and its recept...Ghrelin(Ghrl),an appetite-inducing peptide hormone secreted by the stomach,is the endogenous ligand for the growth hormone secretagogue receptor(Ghs-r).In this study,we identified the preproghrelin gene and its receptors in spotted sea bass(Lateolabrax maculatus).The ghrl gene consisted of an open reading frame(ORF)of 324 nucleotides encoding 107 amino acids,and the premature protein contained a 20-amino-acid mature peptide.Through a syntenic analysis,we also validated the annotation of growth hormone secretagogue receptor la(ghs-rla)and growth hormone secretagogue receptor la-1ike(ghs-rla-like),which contained seven-transmembrane structures,in spotted sea bass.The ORF of ghs-rla consisted of 1152 bp that encoded a 383-amino-acid protein,and(ghs-rla-like) contained an ORF of 2631 bp and produced a protein with 876 amino acids.A phylogenetic analysis showed that spotted sea bass ghrl and its receptors clustered with those of other fishes and were more distantly related to those of other vertebrates.In situ hybridization revealed that ghrl was highly expressed in the stomach and localized in the mucosa and submucosa.The expression of these genes varied during short-term starvation in a time-dependent manner.In vitro studies showed that after incubation with Ghrl for 3 h enhanced the expression of motilin(mln),gastrin(gas)and cholecystokinin(cck)、but this effect vanished after 6 h of incubation.In summary,Ghrl and its receptors might play important roles in the regulation of food intake in spotted sea bass.展开更多
One of the goals of the aquaculture industry is to understand and control growth associated traits through selective breeding.In the present study the molecular basis of growth heterogeneity in the European sea bass(D...One of the goals of the aquaculture industry is to understand and control growth associated traits through selective breeding.In the present study the molecular basis of growth heterogeneity in the European sea bass(Dicentrarchus labrax)was addressed.To establish growth heterogeneity in a group of hatchery bred sea bass individuals were tagged and their specific growth rates(SGR)determined at monthly intervals.Gene expression in the brain,liver and white muscle from fish with the most divergent sustained SGR(6 individuals of the first and last quartile)was assessed using SuperSAGE(Serial Analysis Gene Expression)combined with next generation SOLiD4 sequencing.A total of approx.11 million edited tags(26 bp),on average 2 million tags per SAGE library,that represented 47.071 unique transcripts were identified.Comparison of transcripts in fish with high and low SGR yielded 344,698 and 601 differently expressed tags(0.01%false discovery rate and 4-fold change)in brain,liver and muscle,respectively.The tags were mapped onto the sea bass genome and approximately one third of the tags could be assigned to annotated genes.Pathway enrichment analysis revealed in liver,muscle and brain intricate gene expression changes in endocrine regulatory pathways involved in growth,metabolic and the stress axis,underlying divergent SGR in sea bass.展开更多
In the present work, we compared indices of metabolism and feed conversion efficiency of a semi benthic and two pelagic mari-cultured fish species in the Mediterranean Sea. The metabolism of fish species varies accord...In the present work, we compared indices of metabolism and feed conversion efficiency of a semi benthic and two pelagic mari-cultured fish species in the Mediterranean Sea. The metabolism of fish species varies according to habitat and ecophysiological adaptations. For example, with increasing depth, some species may exhibit adaptations to lower temperature and hypoxic conditions with a reduction in mass specific metabolic rate. Meagre （Argyrosomus regius） is a semi-benthic fish found at depths between 30 m and 300 m. Sea bass （Dicentrarhus labrax） and gilthead sea bream （Sparus auratus） are semi-pelagic fish species widely cultivated in the Mediteranean Sea. The aerobic metabolic potential and feed conversion efficiency of meagre were very different from the sea bass and gilthead sea bream. Compared to these two semic-pelagic fish species, meagre exhibited less efficient feed conversion rate, fillet yield. The results provide an estimate of the quantity of fish required to produce 1 kg of fillet weight, an estimation which is required for the operational management of fish processing companies and for estimating the wastes of fish processing factories during filleting.展开更多
The objective of the study was to investigate the efficiency of slurry ice during harvesting and transportation of European sea bass(Dicentrarchus labrax)to retain flesh quality and extend shelf life,compared with con...The objective of the study was to investigate the efficiency of slurry ice during harvesting and transportation of European sea bass(Dicentrarchus labrax)to retain flesh quality and extend shelf life,compared with conventional flake ice.Fish was slaughtered and transported in different mixtures of slurry ice and conventional flake ice(C:slaughtered and transported in 100%flake ice-Control samples,SC:slaughtered in 100%slurry ice and transported in 100%flake ice,S50:slaughtered and transported in 50%slurry ice-50%flake ice,S100:slaughtered and transported in 100%slurry ice)and subsequently stored under controlled isothermal conditions at 0℃for shelf life modelling and flesh quality evaluation(proteolytic enzymes).The replacement of conventional flake ice with slurry ice as a slaughtering method led to improved quality stability during subsequent refrigerated storage and shelf life extension,in terms of microbial growth,flesh quality and sensory degradation of fish.Based on microbial growth,the shelf life of C samples was found to be 19 days,whereas the shelf life of S50/S100 and SC was 21 and 25 days,respectively,showing that the replacement of flake ice with slurry ice resulted in 2–6 days shelf life extension of whole sea bass stored at 0℃.The use of slurry ice at slaughter and flake ice in transportation was accompanied by low activities and late peaks of all four enzymes that is expected to lead to delayed proteolytic degradation and extended freshness.展开更多
基金the Science and Technology Planning Project in FujianChina(No.2015N0010)+1 种基金the Science and Technology Planning Project in XiamenChina(No.3502Z20143017)。
文摘The aquaculture industry has developed significantly over the past few decades and has had a substantial impact on the global food supply and marine fisheries resources.However,some problems arise behind the scenes due to excessive intensive farming,such as slow animal growth,frequent disease,and lipid metabolism disorders.These problems have limited the sustainable development of the aquaculture industry,and a continuable solution is required.The use of fungal polysaccharide appears to provide a solution to these problems.Therefore,different supplemented levels of Poria cocos polysaccharide(PCP)(0,0.4,0.8,1.2,1.6,and 2.0 g/kg,respectively)were fed to spotted sea bass(Lateolabrax maculatus)in similar size(30.28±0.18 g)in current study.The effects of PCP on growth,physiological parameters,and lipid metabolism of spotted sea bass were investigated after a 4-week rearing period.Results showed,fish with PCP intake presented a significantly higher weight gain,specific growth rate,and a significantly lower feed conversion ratio.Significantly higher trypsin activity in liver and intestine were observed in fish with PCP intake.The superoxide dismutase activity in serum and liver of fish with PCP intake were significantly improved,while significantly higher serum total antioxidant capacity and hepatic catalase activity were also observed.However,no significant differences in lysozyme and alkaline phosphatase activity were evident among groups.Fish with PCP intake showed a significantly lower total cholesterol,but no noteworthy change in triglyceride and lipid-metabolismrelated genes expression were observed among groups.Results indicated that intake of PCP has a positive effect on growth and antioxidant capacity of spotted sea bass,but seems to have a limited effect on the non-specific immunity and lipid metabolism of spotted sea bass.Based on the regression analysis results,1.4 g/kg of PCP is the optimal dose for spotted sea bass in size(30.28±0.18 g).
基金the National Key R&D Program of China(No.2020YFD0900204)the National Natural Science Foundation of China(No.32072947)+1 种基金the China Agriculture Research System of MOF and MARA(No.CARS-47)the KU-OUC Dual Master’s Program and Ocean University of China Scholarship Council。
文摘The caspase gene family is a crucial gene cluster that regulates apoptosis which contribute to programmed cell death,cell proliferation and differentiation,and several immune responses.In our study,a complete set of 12 caspase genes were identified in spotted sea bass Lateolabrax maculatus.These genes were divided into three subfamilies:2 inflammatory caspases(casp-1 and casp-14-like),5 apoptosis initiators(casp-2,casp-8a,casp-8b,casp-9,and casp-10),and 5 apoptosis executioners(casp-3a,casp-3b,casp-3-like,casp-6,and casp-7).Their phylogenetic relationships,synteny and gene structures were systematically analyzed.Furthermore,the relative expression profiles of the caspase family members in the liver,intestine,head kidney,and spleen were measured by q PCR after infection with Vibrio harveyi.The results showed that the overall mRNA levels of the caspase genes were dramatically increased after V.harveyi infection,and the expression patterns varied among genes and tissues.More caspase genes underwent pronounced expression changes in the head kidney and spleen than in the liver or intestine,mainly after 48 h of the challenge.Specifically,casp-3a,casp-3b,casp-3-like,casp-6,casp-7,casp-8a,casp-8b,casp-10,and casp-14-like in the head kidney,and casp-3-like,casp-6,casp-7,and casp-14-like in the spleen,were the most responsive caspase genes which may contribute significantly to immune regulation in spotted sea bass.Additionally,the apoptosis level in head kidney and spleen after infection were examined using the Caspase assay.Our study provides a systemic overview of the caspase gene family in spotted sea bass after V.harveyi infection and lays a foundation for further deciphering the biological roles of these caspase genes.
基金supported by the National Natural Science Foundation of China(31772876)Zhejiang Provincial Natural Science Foundation of China(LZ18C190001)+1 种基金Scientific Innovation Team Project of Ningbo(2015C110018)K.C.Wong Magna Fund in Ningbo University
文摘D-dopachrome tautomerase(DDT),a member of the macrophage migration inhibitory factor(MIF)protein superfamily,is a newly described cytokine with chemokine-like characteristics.However,research on fish DDT remains limited.In this study,we identified a DDT homolog(LjDDT)from the Japanese sea bass,Lateolabrax japonicus.Sequence analysis showed that LjDDT had typical sequence features of known DDT and MIF homologs and was most closely related to DDT of rock bream(Oplegnathus fasciatus).LjDDT transcripts were detected in all tested tissues of healthy Japanese sea bass,with the highest expression found in the liver.Upon infection with Vibrio harveyi,LjDDT transcripts were significantly down-regulated in the three tested tissues,including the liver,spleen,and head kidney.Recombinant LjDDT(rLjDDT)and the corresponding antibody(anti-rLjDDT)were subsequently prepared.The administration of 100μg/g anti-rLjDDT had a statistically significant protective effect on the survival of V.harveyi-infected fish.Moreover,rLjDDT was able to induce the migration of monocytes/macrophages(MO/MФ)and lymphocytes both in vitro and in vivo,but without significant influence on the migration of neutrophils.rLjDDT exhibited chemotactic activity for lipopolysaccharide(LPS)-stimulated M1-type MO/MΦin vitro,but not for cAMP-stimulated M2-type MO/MΦ.Furthermore,the knockdown of LjCD74,but not LjCXCR4,significantly down-regulated the rLjDDT-enhanced migration of MO/MΦand relieved the rLjMIF-inhibited migration of MO/MΦ.These results indicate that LjCD74 may be the major chemotactic receptor of LjDDT and LjMIF in Japanese sea bass MO/MΦ.Combined rLjDDT+rLjMIF treatment had no significant effect on the migration of MsiRNA,LjCD74si-,or LjCXCR4sitreated MO/MΦcompared to the control group,suggesting that the roles of LjDDT and LjMIF may be antagonistic.In conclusion,our study demonstrates for the first time that DDT may play a role in the immune responses of fish against bacterial infection through chemotactic recruitment of MO/MΦvia mediation of CD74 as an antagonist of MIF.
基金supported by the National Key Technologies R&D Program of China(2011BAD13B03)
文摘The RNA helicase Vasa is an important regulator of primordial germ cell development. Its function in mature fish, espe- cially the hormone-related differences in maturing male fish has seldom been documented. In this study, a full length cDNA sequence of the vasa gene was cloned from Japanese sea bass, Lateolabraxjaponicas, and it was namedjsb-vasa. Homology analysis showed thatjsb-vasa was closely related to its teleost homologs. The spatial distribution ofjsb-vasa indicated that it was only highly ex- pressed in testis, showing its germ cell-specific expression pattern. During the testicular development cycle, jsb-vasa was highly expressed during early period of spermatogenesis, and reduced when spermatogenesis advanced. In addition, the jsb-vasa gene ex- pression was significantly inhibited at 6 h, 12 h and 24 h after injecting hCG （human ehorionic gonadotropin） and GnRHa （Gonad- otropin-releasing hormone analogue）, indicating thatjsb-vasa gene may play an important role in spermatogenesis of Japanese sea bass, and be under the regulation of external sex hormones.
基金the Natural Science Foundation of China (NSFC) (grant No. 30972274)the Ministry of Science and Technology (MOST) of China (grant No. 2008AA09260)
文摘Previous studies have shown the existence of a complement system in the amphioxus Branchiostoma japonicum.How-ever,whether it has an opsonic activity similar to that of vertebrates remains unknown.We demonstrated that the humoral fluid(HF)of amphioxus promoted the phagocytosis of yeast cells with sea bass(Lateolabrax japonicus)macrophages,whereas the C3-depleted and heated HF significantly lost the phagocytosis-promoting capacity.In addition,the precipitation of factor B(Bf)led to a marked loss of opsonic activity.Moreover,C3 fragments in the HF were found to bind to yeast cell surfaces.The results indicate that the amphioxus complement system is an important element involved in the opsonic activity,which promotes the sea bass macrophage phagocytosis by tagging yeast cells with C3 fragments via the activation of alternative complement pathway.
文摘In this study, trace metals [Cadmium (Cd), Mercury (Hg) and Lead (Pb)] consentration of 76 pieces of frozen European sea bass (Dicentrarchus labrax Linnaeus-1758) and gilthead sea bream (Sparus aurata Linnaeus-1758) fillets, produced and marketed in Turkey, were determined using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) after microwave damp burning process, and results obtained were assessed in terms of public health. This study was conducted from June 2010 to July 2011. At the end of study, maximum heavy metal levels for sea bass and sea bream fillets were determined as 256.50, 216.22 μg/kg for Cd;414.79, 338.46 μg/kg for Hg ve 1047.61, 147.14 μg/kg for Pb, respectively. At the end of the study, the levels of cadmium (for 3 samples) and lead (for 1 samples) were higher than the recommended legal limits of the European Union for human consumption. It was detected that the fillets which were analyzed was good quality from the point of cadmium, mercury and lead contents.
文摘The effect of chitosan incorporated into feed formulation on the growth, feed utilization, body composition and histological response of sea bass (Dicentrarchus labrax) was investigated. Final fish weight, feed conversion ratio (FCR), specific growth rate (SGR), protein efficiency ratio (PER), protein productive value (PPV), and energy utilization (EU) of sea bass feed chitosan supplemented diet and the control diet were determined at the end of experiment. Data presents mean ± SD from triplicate determination (n = 3) for 75 days feeding trial. Different concentrations (0.5, 1.0, 2.0, 3.0 & 4.0) and control without chitosan incorporated with total fish feed in the form of dry diets were fed for 75 days. Average final weight (FW) was significantly higher at diet 3 (1 g?kg?1 chitosan) and the lowest in control fish group, specific growth rate (SGR) was significant at diet 3. Also, protein efficiency ratio (PER), protein productive value (PPV), and energy utilization (EU) showed the same trend. The chemical body composition, crude protein, dry matter, crude fat and ash were significant (P ≤ 0.01) different compared to control groups. The present investigation suggested that the chitosan incorporated into diets of sea bass fish certainly enhanced the non specific responses and reduced mortality and also improved the growth performance of fish.
文摘The effects of dietary garlic (Allium sativum) powder as a feed additive on hematological and biochemical health characteristics of European Sea bass Dicentrarchus labrax juveniles were studied. Experimental fish were fed diets supplemented with garlic powder at 0 (control), 2%, 4%, or 6% levels for a period of 60 days. Results showed that the red blood cell count (RBC), hemoglobin (Hb) concentration, hematocrit (%), and mean corpuscular Hb in fish fed garlic powder diets at dietary inclusion levels of 4% and 6%, were significantly lower than the control values. Serum glucose was significantly lower in Sea bass that were fed garlic powder diets (4% and 6%) compared to the control group. Serum triglyceride and globulin levels in fish fed a 4% garlic powder diet were significantly higher than the control values, whereas these two variables in the 2% and 6% garlic treatments were similar to the control values. The cholesterol levels in the 2% and 6% treatment groups were lower than the value recorded for the control group. As a result, it is suggested that garlic powder supplementation in diets for Sea bass juveniles should not exceed 2%. The present study is the first attempt to examine the effects of dietary garlic powder on the hematological and biochemical status in Sea bass juveniles.
基金supported by the“Department of Excellence-2018”Program(Dipartimenti di Eccellenza)of the Italian Ministry of Education,University and Research,DIBAF-Department for Innovation in Biological,Agro-food and Forest Systems,University of Tuscia,Project“Landscape 4.0-food,wellbeing and environment”.
文摘This review summarizes the current knowledge on immune defence activities of the European sea bass Dicentrarchus labrax by reporting the consistent amount of work done on this economically-important species.A draft genome sequence is available for this species,together with whole transcriptomes from lymphoid and non-lymphoid tissues.Available full-length coding sequences of many immunoregulatory and immune-related genes allow for targeted quantitative PCR analysis,nowadays needed for-omics data verification,ex vivo and in vitro.The first anti-T cells monoclonal antibody teleost-wise was obtained in sea bass,followed by several monoclonal and polyclonal markers of lymphocyte populations,namely T cells(pan-T,CD3ε,TcRγ,CD45),and B cells(IgM,IgT,IgD).The combined use of molecular and biochemical tools enabled investigations on innate and acquired immune responses of sea bass in unstimulated/stimulated fish,along the development and under variable environmental conditions and food regimes.An overview of sea bass viral and bacterial pathogens and available vaccines against these microorganisms is also provided.The knowledge accumulated in the past 25 years validates the European sea bass as a reference marine model in the field of fish immunology.
基金supported by National Key R&D Program of China(2019YFD0901602)China Agriculture Research System(CARS-47-G26)Ability promotion project of Shanghai Municipal Science and Technology Commission Engineering Center(19DZ2284000).
文摘This study was aimed at preparing chitosan(CS)-phenolic acids copolymers to obtain better preservation effect in marine products.In this work,CS was grafted onto phenolic acids such as gallic acid(GA)and protocatechuic acid(PA)by a carbodiimide coupling method.The copolymers(CS-grafted-GA(CS-g-GA)and CS-grafted-PA(CS-g-PA))were further confirmed through physicochemical properties including ultraviolet-visible(UV-Vis)spectrophotography,fourier transform infrared(FTIR)spectrometry,differential scanning calorimetry(DSC)thermogram,rheological behaviour,scanning electron microscope(SEM)and antioxidant activity analysis.Subsequently,the effects of copolymers on preservation of refrigerated sea bass(Lateolabrax japonicus)fillets were investigated.The results showed that the CS-g-GA(110.82 mg GA/g)exhibited higher grafting rate than CS-g-PA(62.63 mg PA/g).According to the assessment of UV-Vis and FTIR spectrometry,both the GA and PA were grafted onto CS successfully.SEM analysis demonstrated that the microstructure of copolymers became irregular.Meanwhile,both the CS-g-GA and CS-g-PA copolymers displayed superior thermal stability,rheological properties and antioxidant capacity than the pure CS.Furthermore,the copolymers also revealed a significantly stronger preservation effect on sea bass fillets including inhibiting microbial growth and delaying the deterioration of color,texture and sensory quality.Therefore,CS-g-GA and CS-g-PA could be used as promising preservatives for seafood.
基金supported by two research grants(R202007 and R202107)from BNU-HKBU United International College,China.
文摘Sea bass(Lateolabrax maculatus)is one of the important seafood in China.Its shelf-life under refrigerated storage exponentially deteriorate due to the growth of spoilage microorganisms,protein degradation and lipid oxidation.In this study,4 coating materials namely,konjac glucomannan-whey protein isolate(KGM-WPI)film,chitosan-sweet potato starch(CHI-SPS)film,chitosan-bamboo fungus(CHI-BF)film,and chitosan-boehmite alumina(CHI-BAH)have been explored to enhance the shelf life of sea bass during 8 days of refrigerated storage.Overall,CHI-BF was observed to be best in retaining hardness,gumminess and maintaining total volatile basic nitrogen value.Whereas CHI-SPS was found to retain chewiness and maintain lower values for drip loss and peroxide value.CHI-BAH coating was observed to maintain the lower values for pH and EC values of sea bass under refrigerated storage.However,the least increase in total viable count and minimum change in b^(*)value was observed in the case of sea bass coated with KGM-WPI.The current research fi ndings provide a new practical storage method for the entire fresh fish.The fresh fish can be coated with different coating materials and store on the ice at 4℃without packaging during retailing.These film coated whole fresh fish retains its microbial and sensory quality.
基金This work was supported by the National Key R&D Program of China(Grant number 2018YFD0900101)the China Agriculture Research System(CARS-47)the Key Laboratory of Mariculture(KLM),Ministry of Education,Ocean University of China(2018008)。
文摘Ghrelin(Ghrl),an appetite-inducing peptide hormone secreted by the stomach,is the endogenous ligand for the growth hormone secretagogue receptor(Ghs-r).In this study,we identified the preproghrelin gene and its receptors in spotted sea bass(Lateolabrax maculatus).The ghrl gene consisted of an open reading frame(ORF)of 324 nucleotides encoding 107 amino acids,and the premature protein contained a 20-amino-acid mature peptide.Through a syntenic analysis,we also validated the annotation of growth hormone secretagogue receptor la(ghs-rla)and growth hormone secretagogue receptor la-1ike(ghs-rla-like),which contained seven-transmembrane structures,in spotted sea bass.The ORF of ghs-rla consisted of 1152 bp that encoded a 383-amino-acid protein,and(ghs-rla-like) contained an ORF of 2631 bp and produced a protein with 876 amino acids.A phylogenetic analysis showed that spotted sea bass ghrl and its receptors clustered with those of other fishes and were more distantly related to those of other vertebrates.In situ hybridization revealed that ghrl was highly expressed in the stomach and localized in the mucosa and submucosa.The expression of these genes varied during short-term starvation in a time-dependent manner.In vitro studies showed that after incubation with Ghrl for 3 h enhanced the expression of motilin(mln),gastrin(gas)and cholecystokinin(cck)、but this effect vanished after 6 h of incubation.In summary,Ghrl and its receptors might play important roles in the regulation of food intake in spotted sea bass.
基金The authors acknowledge funding by the European Commission of the European Union through the Network of Excellence Marine Genomics Europe(contract GOCE-CT-2004-505403)by the Portuguese Foundation for Science and Technology(FCT)through project CMAR/Multi/04326/2013+3 种基金grants to BL(SFRH/BD/29171/2006)PISP(SFRH/BPD/25247/2005)RSTM(SFRH/BPD/66742/2009)BL benefited from a SABRETRAIN Marie Curie EST fellowship.
文摘One of the goals of the aquaculture industry is to understand and control growth associated traits through selective breeding.In the present study the molecular basis of growth heterogeneity in the European sea bass(Dicentrarchus labrax)was addressed.To establish growth heterogeneity in a group of hatchery bred sea bass individuals were tagged and their specific growth rates(SGR)determined at monthly intervals.Gene expression in the brain,liver and white muscle from fish with the most divergent sustained SGR(6 individuals of the first and last quartile)was assessed using SuperSAGE(Serial Analysis Gene Expression)combined with next generation SOLiD4 sequencing.A total of approx.11 million edited tags(26 bp),on average 2 million tags per SAGE library,that represented 47.071 unique transcripts were identified.Comparison of transcripts in fish with high and low SGR yielded 344,698 and 601 differently expressed tags(0.01%false discovery rate and 4-fold change)in brain,liver and muscle,respectively.The tags were mapped onto the sea bass genome and approximately one third of the tags could be assigned to annotated genes.Pathway enrichment analysis revealed in liver,muscle and brain intricate gene expression changes in endocrine regulatory pathways involved in growth,metabolic and the stress axis,underlying divergent SGR in sea bass.
文摘In the present work, we compared indices of metabolism and feed conversion efficiency of a semi benthic and two pelagic mari-cultured fish species in the Mediterranean Sea. The metabolism of fish species varies according to habitat and ecophysiological adaptations. For example, with increasing depth, some species may exhibit adaptations to lower temperature and hypoxic conditions with a reduction in mass specific metabolic rate. Meagre （Argyrosomus regius） is a semi-benthic fish found at depths between 30 m and 300 m. Sea bass （Dicentrarhus labrax） and gilthead sea bream （Sparus auratus） are semi-pelagic fish species widely cultivated in the Mediteranean Sea. The aerobic metabolic potential and feed conversion efficiency of meagre were very different from the sea bass and gilthead sea bream. Compared to these two semic-pelagic fish species, meagre exhibited less efficient feed conversion rate, fillet yield. The results provide an estimate of the quantity of fish required to produce 1 kg of fillet weight, an estimation which is required for the operational management of fish processing companies and for estimating the wastes of fish processing factories during filleting.
基金This research was funded by the Greek Operational Programme for Fisheries,Priority Axis“Innovation in Aquaculture”,Project title:“Development and application of novel methods for fish harvesting and processing for quality improvement and shelf life extension”(2018-2021)。
文摘The objective of the study was to investigate the efficiency of slurry ice during harvesting and transportation of European sea bass(Dicentrarchus labrax)to retain flesh quality and extend shelf life,compared with conventional flake ice.Fish was slaughtered and transported in different mixtures of slurry ice and conventional flake ice(C:slaughtered and transported in 100%flake ice-Control samples,SC:slaughtered in 100%slurry ice and transported in 100%flake ice,S50:slaughtered and transported in 50%slurry ice-50%flake ice,S100:slaughtered and transported in 100%slurry ice)and subsequently stored under controlled isothermal conditions at 0℃for shelf life modelling and flesh quality evaluation(proteolytic enzymes).The replacement of conventional flake ice with slurry ice as a slaughtering method led to improved quality stability during subsequent refrigerated storage and shelf life extension,in terms of microbial growth,flesh quality and sensory degradation of fish.Based on microbial growth,the shelf life of C samples was found to be 19 days,whereas the shelf life of S50/S100 and SC was 21 and 25 days,respectively,showing that the replacement of flake ice with slurry ice resulted in 2–6 days shelf life extension of whole sea bass stored at 0℃.The use of slurry ice at slaughter and flake ice in transportation was accompanied by low activities and late peaks of all four enzymes that is expected to lead to delayed proteolytic degradation and extended freshness.
