Tissues Of Carp Research Articles

Molecular cloning, tissue distribution, and pharmacological characterization of melanocortin-4 receptor in grass carp (Ctenopharyngodon idella)

Melanocortin-4 receptor (MC4R) plays a pivotal role in the mediation of leptin action on food intake and energy expenditure in mammals. The MC4R has also been identified in several teleosts, and its importance in the regulation of fish energy homeostasis is emerging. We herein reported on the molecular cloning, tissue distribution, and pharmacological characterization of MC4R in grass carp (Ctenopharyngodon idella), an economically and ecologically important fish. We showed that grass carp MC4R (ciMC4R) consisted of a 981 bp open reading frame encoding a protein of 326 amino acids, highly homologous (>95%) to several teleost MC4Rs. Phylogenetic and synteny analysis further indicated ciMC4R was closely related to piscine MC4Rs. Using reverse transcription PCR, we found that mc4r messenger RNA was expressed in the brain as well as various peripheral tissues in grass carp. The pharmacological properties of ciMC4R were investigated using 4 agonists, including α-melanocyte stimulating hormone (α-MSH), β-MSH, [Nle4, D-Phe7]-MSH (NDP-MSH), and adrenocorticotropic hormone (ACTH). We showed that all 4 ligands could bind to ciMC4R and initiate dose-dependent intracellular cyclic adenosine monophosphate (cAMP) accumulation. Grass carp MC4R had the highest affinity for NDP-MSH. Both NDP-MSH and ACTH (1–24) exhibited higher potencies compared to the other 2 endogenous agonists. The ciMC4R was constitutively active, with significantly increased basal cAMP level compared with that of human MC4R (P < 0.01). The availability of ciMC4R and its pharmacologic characteristics provide a basis for future investigation of its functional roles in regulating diverse physiological processes and novel insights into understanding the mechanism of food habit transition in grass carp.

Heavy metals in the common carp (Cyprinus carpio L.) from three reservoirs in the Czech Republic

Toxic metals (cadmium, lead, and mercury) in the tissues of common carp fished from three reservoirs (Pilská, Domaninský, and Matějovský) in the Bohemian-Moravian Highlands were measured in the period from April 2013 to September 2014 and the risk of consuming the fish from these localities was evaluated. During this project 25 fish specimens from each locality were analysed. The concentration of metals in muscle tissue and liver was determined by atomic absorption spectrometry. A variation in the content of heavy metals in fish samples and fish tissues was demonstrated and discussed. Higher concentrations of cadmium in the fish tissue were found in 50 samples of carp liver. Because the fish liver is not commonly consumed, common carp from the Moravian-Moravian Highlands does not pose any health risk for consumers. Concentrations of the other monitored toxic metals in fish tissue were low and were complying with the maximum residue limit in all cases.

Influence of zeolites on lead and cadmium content in separate links of trophic chain in hydroecosystems

Information about the influence of zeolite used as adsorbent to reduce the concentration of Lead and Cadmium in separate links of trophic chain of hydroecosystem namelyn in water, phytoplankton and muscular tissue of Silver carp is given in the article. As a sorbent we used zeolite of Sokirnitsa deposit (village Sokirnitsa, Khust district Transcarpathian region) of fraction 1.0 – 4.0 mm. Investigations were made at the Lviv research station of Institute of fisheries NAAS (Lviv oblast, Horodok region, Velykyi Lyubin). The sorption properties of natural Transcarpathian clinoptilolite towards Lead and Cadmium at dynamic conditions have been studied. The paper represents research results aimed at estimating effectiveness of removing of Lead and Cadmium ions from hydroecosystems using natural mineral–zeolite. The dynamics of heavy metals content at phytoplankton and muscular tissue of silver carp (Hypophthalmichthys molitrix Valenciennes, 1844) was studied. Measurements were perfomed in pond № 24 (12) area 0.14 hectares which is fed by waters of the river Vereshchytsia. The pond depth is 1 – 1.5 meters. Results of investigations worked out statistically combining the groups. Considerable lowering of ions content of both metals in water was determined. The lowering of cadmium content in muscular tissue of Silver carp was much noticeable than the content of Lead. Results of such investigations are rather actual and perspective and will help to reduce the content of some toxicants in water medium. Improvement of water ecosystems after use of natural sorbents will guarantee ecologically safe products of fish culture and will increase the efficiency of the branch.

Targeted genomic enrichment and sequencing of CyHV-3 from carp tissues confirms low nucleotide diversity and mixed genotype infections.

Koi herpesvirus disease (KHVD) is an emerging disease that causes mass mortality in koi and common carp, Cyprinus carpio L. Its causative agent is Cyprinid herpesvirus 3 (CyHV-3), also known as koi herpesvirus (KHV). Although data on the pathogenesis of this deadly virus is relatively abundant in the literature, still little is known about its genomic diversity and about the molecular mechanisms that lead to such a high virulence. In this context, we developed a new strategy for sequencing full-length CyHV-3 genomes directly from infected fish tissues. Total genomic DNA extracted from carp gill tissue was specifically enriched with CyHV-3 sequences through hybridization to a set of nearly 2 million overlapping probes designed to cover the entire genome length, using KHV-J sequence (GenBank accession number AP008984) as reference. Applied to 7 CyHV-3 specimens from Poland and Indonesia, this targeted genomic enrichment enabled recovery of the full genomes with >99.9% reference coverage. The enrichment rate was directly correlated to the estimated number of viral copies contained in the DNA extracts used for library preparation, which varied between ∼5000 and ∼2×107. The average sequencing depth was >200 for all samples, thus allowing the search for variants with high confidence. Sequence analyses highlighted a significant proportion of intra-specimen sequence heterogeneity, suggesting the presence of mixed infections in all investigated fish. They also showed that inter-specimen genetic diversity at the genome scale was very low (>99.95% of sequence identity). By enabling full genome comparisons directly from infected fish tissues, this new method will be valuable to trace outbreaks rapidly and at a reasonable cost, and in turn to understand the transmission routes of CyHV-3.

Histopathological effects following short-term coexposure of Cyprinus carpio to nanoparticles of TiO2 and CuO

The aim of this research was to investigate the coexposure of nanoparticles of titanium dioxide (TiO2) and copper oxide (CuO) on the alterations of the gill, intestine, kidney, and liver tissues of carps (Cyprinus carpio). In this study, carps (length 23±1.5cm; weight 13±1.3g) were divided into six groups of 15 each and exposed to 2.5 and 5.0mgL(-1) of CuO nanoparticles (NPs), 10.0mgL(-1) of TiO2 NPs, and 2.5 and 5.0mgL(-1) of CuO NPs + 10.0mgL(-1) of TiO2 NP mixture. Fish were sampled for histopathological studies after hematoxylin-eosin staining. Results indicated that the more kinds of histopathology anomalies observed with CuO NP and TiO2 NP mixture were broadly of the same type as CuO NPs and TiO2 NPs alone, but the severity or incidence of injuries of gill, intestine, liver, and kidney of carps in the mixture of CuO NPs + TiO2 NPs was higher than that of each NP alone. Moreover, behavioral changes in carps exposed to CuO NP and TiO2 NP mixture such as hyperactivity, loss of balance, and convulsions were higher than those to CuO NPs and TiO2 NPs alone. In conclusion, the presence of TiO2 NPs enhanced the effects of NPs of copper oxide in terms of histopathological changes in carps.

Copper Bioaccumulation and Depuration in Common Carp (Cyprinus carpio) Following Co-exposure to TiO2 and CuO Nanoparticles.

Metal oxide nanoparticles (NPs), such as TiO2 and CuO, are widely applied in an increasing number of products and applications, and therefore their release to the aquatic ecosystems is unavoidable. However, little is known about joint toxicity of different NPs on tissues of aquatic organisms, such as fish. This study was conducted to assess the uptake and depuration of Cu following exposure to CuO NPs in the presence of TiO2 NPs in the liver, intestine, muscle, and gill of common carp, Cyprinus carpio. Carps with a mean total length of 23±1.5cm and mean weight of 13±1.3g were divided into 6 groups of 15 each (1 control group) and exposed to TiO2 NPs, CuO NPs, and a mixture of TiO2 and CuO NPs for periods of 20days for uptake and 10days for depuration. The determination of total Cu concentration was carried out by an ICP-OES. The order of Cu uptake in different tissues of the carps was liver>gill>muscle>intestine in both levels of CuO NPs alone; results showed that the total Cu concentrations in the presence of TiO2 nanoparticles were increased and were in the sequence of liver>gill>intestine>muscle. In depuration period, Cu concentrations were decreased in all treatments in the sequence of gill>intestine>muscle>liver. Uptake of Cu in different tissues of common carp increased with increasing concentration and time and was tissues- and time-dependent. In conclusion, this study suggested that the uptake of Cu in the tissues of common carp increased in the joint presence of TiO2 NPs.

Coexisting of titanium dioxide nanoparticles and diazinon on histopathology of common carp (Cyprinus carpio)

The purpose of present study was to determine the sub-acute toxicity effects of diazinon on the gill and intestine tissues histopathology of common carp (Cyprinus carpio) in exposure to TiO2 NPs. In this study, common carp (length: 21 ± 1.3 cm; weight: 11 ± 1.1 g) were assigned randomly to 12 experimental groups (15 each) and exposed to three non-lethal concentration of TiO2 NPs, two non-lethal concentrations of diazinon, and six mixture concentrations of diazinon and TiO2 NPs, as well a control group for a period of 14 days. For studies of classic histological, the samples of gill and intestine organs were prepared and stained by hematoxylin-eosin and, finally, was imagined by light microscopy. Compared to the control group, gill and intestine tissues of common carp in treatment groups, TiO2, diazinon, and a mixture of TiO2 and diazinon, showed higher histopathological alterations. The most commonly observed alterations in gill were hyperplasia, fusion of lamellae, aneurism, and necrosis. Common alterations in intestine were degeneration, increase in the number of goblet cells, increase in the number of lymphocyte, vacuolation, and necrosis and erosion. In conclusion, this research suggested that the coexistence toxicity of diazinon and TiO2 NPs on the gill and intestine histopathology of common carp was higher than the diazinon and TiO2 NPs alone.

A full-body transcriptome and proteome resource for the European common carp.

BackgroundThe common carp (Cyprinus carpio) is the oldest, most domesticated and one of the most cultured fish species for food consumption. Besides its economic importance, the common carp is also highly suitable for comparative physiological and disease studies in combination with the animal model zebrafish (Danio rerio). They are genetically closely related but offer complementary benefits for fundamental research, with the large body mass of common carp presenting possibilities for obtaining sufficient cell material for advanced transcriptome and proteome studies.ResultsHere we have used 19 different tissues from an F1 hybrid strain of the common carp to perform transcriptome analyses using RNA-Seq. For a subset of the tissues we also have performed deep proteomic studies. As a reference, we updated the European common carp genome assembly using low coverage Pacific Biosciences sequencing to permit high-quality gene annotation. These annotated gene lists were linked to zebrafish homologs, enabling direct comparisons with published datasets. Using clustering, we have identified sets of genes that are potential selective markers for various types of tissues. In addition, we provide a script for a schematic anatomical viewer for visualizing organ-specific expression data.ConclusionsThe identified transcriptome and proteome data for carp tissues represent a useful resource for further translational studies of tissue-specific markers for this economically important fish species that can lead to new markers for organ development. The similarity to zebrafish expression patterns confirms the value of common carp as a resource for studying tissue-specific expression in cyprinid fish. The availability of the annotated gene set of common carp will enable further research with both applied and fundamental purposes.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-3038-y) contains supplementary material, which is available to authorized users.

Simultaneous determination of aditoprim and its three major metabolites in pigs, broilers and carp tissues, and its application in tissue distribution and depletion studies

ABSTRACTAditoprim (ADP) is a recently developed dihydrofolate reductase inhibitor that has shown promise for therapeutic use in veterinary medicine because of its excellent pharmacokinetic properties. In this study, a sensitive and reliable multi-residue chromatography-ultraviolet (HPLC-UV) method for the quantitative analysis of ADP and its three major metabolites was developed, and the tissue distribution and depletion profiles of ADP and its major metabolites in pigs, broilers and carp were investigated. Edible and additional tissues (heart, lung, stomach, intestine and swim bladder) were collected for analysis at six different withdrawal periods after ADP administration for 7 days. ADP, N-monomethyl-ADP and N-didesmethyl-ADP were detected in almost all tissues in the three species. The liver, kidney and lung showed higher residue concentrations, and the liver showed a longer residue half-life (t1/2) than other tissues. In the liver, ADP was the most abundant component with the longest persistence. The results suggest that the liver was the residual target tissue and ADP was the marker residue, and the conclusive withdrawal time (WDT) of 20 days in pigs, 16 days in broilers and 25 days in carp was estimated using the assessment methodologies approved by the Joint FAO/WHO Expert Committee on Food Additives (JECFA).

Alteration of parameters of energy metabolism and ATPase enzymatic system in juvenile common carp (Cyprinus carpio) chronically exposed to tributyltin

The effect of long-term exposure to tributyltin (TBT) on energy metabolism and adenosine triphosphatase (ATPase) enzymatic system in freshwater teleost was investigated. The impact on the parameters of energy metabolism (the content of glucose (Glu) and lactate (LA), and the activities of hexokinase (HK), pyruvate kinase (PK), and lactate dehydrogenase(LDH)) in the muscle tissue, as well as on the ATP enzymatic system (ATP content, Total-ATPase, Na+-K+-ATPase, and Ca2+-Mg2+-ATPase) in the gill tissue of common carp was evaluated. Fish were exposed to sublethal concentrations of TBT (75, 0.75, and 7.5 µg/l) for 60 days. Based on the results, long-term exposure to TBT could lead to obvious ATP enzymatic system responses, including the decreased ATP content and Na+-K+-ATPase activity, and the increased activities of Total-ATPase and Ca2+-Mg2+-ATPase. Moreover, the parameters of energy metabolism in muscle were also regulated, such as induced indices of the levels of Glu and LA, and the activities of HK and PK, and inhibited indices of LDH activity. Shortly, the measured physiological responses in fish could provide useful information to better understand the mechanisms of TBT-induced bio-toxicity, and could be used as potential biomarkers for monitoring the TBT pollution in the field.

Dependence of the common carp (Cyprinus carpioL.) fatty acid profile on diet composition in a semi-intensive farming system: tissue and time variability

Increasing the amount of n-3 PUFA in carp meat is one of the most important tasks in enhancing its overall quality. However, the relative influence of supplemental feed and natural feed on the FA profile of cultivated carp flesh is not well documented, making it difficult to choose the most efficient strategy. Carp diet composition and diet and flesh fatty acid profiles were simultaneously followed in order to determine the influence of pelleted feed compared to natural feed on fatty acid profiles of carp tissues. Pelleted feed clearly dominated over zooplankton and Chironomidae in the carp diet, producing carp tissue fatty acid profiles closely resembling those of pelleted feed. However, increase in the abundance of zooplankton over the course of the investigation resulting in concomitant increase of its proportion in feed bulk was in strong positive correlation with increase in n-3 HUFA in the dorsal muscle. n-3 PUFA enrichment of supplemental feed could be the dominant mechanism in production of carp meat rich in n-3 PUFA. However, even a small increase in natural feed availability could significantly change the diet of common carp and result in considerable improvement of meat quality with regard to n-3 HUFA content.

Characterization of common carp (Cyprinus carpio L.) interferon regulatory factor 5 (IRF5) and its expression in response to viral and bacterial challenges.

BackgroundCommon carp (Cyprinus carpio L.), one of the most economically valuable commercial farming fish species in China, is often infected by a variety of viruses. As the first line of defence against microbial pathogens, the innate immune system plays a crucial role in teleost fish, which are lower vertebrates. Interferon (IFN) regulatory factor 5 (IRF5) is a key molecule in antiviral immunity that regulating the expression of IFN and other pro-inflammatory cytokines. It is necessary to gain more insight into the common carp IFN system and the function of fish IRF5 in the antiviral and antibacterial response.ResultsIn the present study, we characterized the cDNA and genomic sequence of the IRF5 gene in common carp, and analysed tissue distribution and expression profile of this gene in response to polyinosinic:polycytidylic acid (poly I:C) and lipopolysaccharides (LPS) treatment. The common carp IRF5 (ccIRF5) gene is 5790 bp in length and is composed of 9 exons and 8 introns. The open reading frame (ORF) of ccIRF5 is 1554 bp, and encodes 517 amino acid protein. The putative ccIRF5 protein shares identity (65.4–90.0 %) with other fish IRF5s and contains a DNA binding domain (DBD), a middle region (MR), an IRF-associated domain (IAD), a virus activated domain (VAD) and two nuclear localization signals (NLSs) similar to those found in vertebrate IRF5. Phylogenetic analysis clustered ccIRF5 into the IRF5 subfamily with other vertebrate IRF5 and IRF6 genes. Real-time PCR analysis revealed that ccIRF5 mRNA was expressed in all examined tissues of healthy carps, with high levels observed in the gills and the brain. After poly I:C challenge, expression levels of ccIRF5, tumour-necrosis factor α (ccTNFα) and two IFN stimulated genes [ISGs (ccISG5 and ccPKR)] were up-regulated in seven immune-related tissues (liver, spleen, head kidney, foregut, hindgut, skin and gills). Furthermore, all four genes were up-regulated in vitro upon poly I:C and LPS challenges.ConclusionsOur findings suggest that IRF5 might play an important role in regulating the antiviral and antibacterial response in fish. These results could provide a clue for preventing common carp infection by pathogenic microorganisms present in the aquatic environment.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-016-0750-4) contains supplementary material, which is available to authorized users.

Evidence that ghrelin may be associated with the food intake of gibel carp (Carassius auratus gibelio)

Ghrelin, a non-amidated peptide hormone, is a potent anorectic neuropeptide implicated in feeding regulation in mammals and non-mammalian vertebrates. However, the involvement of ghrelin in the feeding behavior of teleosts has not been well understood. To better understand the role of ghrelin in the regulation of appetite in fish, in this study, we cloned the cDNAs encoding ghrelin and investigated their mRNA distributions in gibel carp tissues. We also assessed the effects of different nutritional status on ghrelin mRNA abundance. Ghrelin mRNAs were ubiquitously expressed in ten tissues (intestine, liver, brain, mesonephron, head kidney, spleen, skin, heart, muscle, gill and pituitary gland), and relatively high expression levels were detected in the gut. Postprandial studies analysis revealed a significant postprandial decrease in ghrelin mRNA expression in the gut (1 and 3h after the regular feeding time). In addition, ghrelin mRNA expression in the gut significantly increased at day 7 after fasting and declined sharply after refeeding, which suggested that ghrelin might be involved in the regulation of appetite in gibel carp. Overall, our result provides basis for further investigation into the regulation of feeding in gibel carp.

Identification and characterization of a LTR retrotransposon from the genome of Cyprinus carpio var. Jian.

A Ty3/gypsy-retrotransposon-type transposon was found in the genome of the Jian carp (Cyprinus carpio var. Jian) in a previous study (unpublished), and was designated a JRE retrotransposon (Jian retrotransposon). The full-length JRE retrotransposon is 5126bp, which includes two long terminal repeats of 470bp at the 5' end and 453bp at the 3' end, and two open reading frames between them: 4203bp encoding the group-specific antigen (GAG) and polyprotein (POL). The pol gene has a typical Ty3/gypsy retrotransposon structure, and the gene order is protease, reverse transcriptase, RNase H, and integrase (PR-RT-RH-IN). A phylogenetic analysis of the pol gene showed that it has similarities of 40.7, 40, and 32.8%, to retrotransposons of Azumapecten farreri, Mizuhopecten yessoensis, and Xiphophorus maculatus, respectively. Therefore, JRE might belong to the JULE retrotransposon family. The copy number of the JRE transposon in the genome of the Jian carp is 124, determined with real-time quantitative PCR. The mRNA of the JRE retrotransposon is expressed in five Jian carp tissues, the liver, kidney, blood, muscle, and gonad, and slightly higher in the kidney and liver than in the other tissues.

Genome-Wide Identification, Characterization and Phylogenetic Analysis of ATP-Binding Cassette (ABC) Transporter Genes in Common Carp (Cyprinus carpio).

The ATP-binding cassette (ABC) gene family is considered to be one of the largest gene families in all forms of prokaryotic and eukaryotic life. Although the ABC transporter genes have been annotated in some species, detailed information about the ABC superfamily and the evolutionary characterization of ABC genes in common carp (Cyprinus carpio) are still unclear. In this research, we identified 61 ABC transporter genes in the common carp genome. Phylogenetic analysis revealed that they could be classified into seven subfamilies, namely 11 ABCAs, six ABCBs, 19 ABCCs, eight ABCDs, two ABCEs, four ABCFs, and 11 ABCGs. Comparative analysis of the ABC genes in seven vertebrate species including common carp, showed that at least 10 common carp genes were retained from the third round of whole genome duplication, while 12 duplicated ABC genes may have come from the fourth round of whole genome duplication. Gene losses were also observed for 14 ABC genes. Expression profiles of the 61 ABC genes in six common carp tissues (brain, heart, spleen, kidney, intestine, and gill) revealed extensive functional divergence among the ABC genes. Different copies of some genes had tissue-specific expression patterns, which may indicate some gene function specialization. This study provides essential genomic resources for future studies in common carp.

Grass carp (Ctenopharyngodon idella) ATF6 (activating transcription factor 6) modulates the transcriptional level of GRP78 and GRP94 in CIK cells.

ATF transcription factors are stress proteins containing alkaline area-leucine zipper and play an important role in endoplasmic reticulum stress. ATF6 is a protective protein which regulates the adaptation of cells to ER stress by modulating the transcription of UPR (Unfolded Protein Response) target genes, including GRP78 and GRP94. In the present study, a grass carp (Ctenopharyngodon idella) ATF6 full-length cDNA (named CiATF6, KT279356) has been cloned and identified. CiATF6 is 4176 bp in length, comprising 159 nucleotides of 5'-untranslated sequence, a 1947 nucleotides open reading frame and 2170 nucleotides of 3'-untranslated sequences. The largest open reading frame of CiATF6 translates into 648 aa with a typical DNA binding domain (BRLZ domain) and shares significant homology to the known ATF6 counterparts. Phylogenetic reconstruction confirmed its closer evolutionary relationship with other fish counterparts, especially with Zebrafish ATF6. RT-PCR showed that CiATF6 was ubiquitously expressed and significantly up-regulated after stimulation with thermal stress in all tested grass carp tissues. In order to know more about the role of CiATF6 in ER stress, recombinant CiATF6N with His-tag was over-expressed in Rosetta Escherichia coli, and the expressed protein was purified by affinity chromatography with Ni-NTA His-Bind Resin. In vitro, gel mobility shift assays were employed to analyze the interaction of CiATF6 protein with the promoters of grass carp GRP78 and GRP94, respectively. The result has shown that CiATF6 could bind to these promoters with high affinity by means of its BRLZ mainly. To further study the transcriptional regulatory mechanism of CiATF6, Dual-luciferase reporter assays were applied. Recombinant plasmids of pGL3-GRP78P and pGL3-CiGRP94P were constructed and transiently co-transfected with pcDNA3.1-CiATF6 (pcDN3.1-CiATF6-nBRLZ, respectively) into C. idella kidney (CIK) cells. The result has shown that CiATF6 could activate CiGRP78 and CiGRP94 promoters.

Analysis of Heavy Metals Concentration in Tissues of Three Different Fish Species Included in Human Diet from Danube River

Abstract The aim of this study was the investigation of water, sediments and fish tissues contamination with heavy metals. All samples were taken from the Danube River in Belgrade region, a location upstream from Batajnica. Concentrations of Cd, Hg and Pb in water samples were not detected, while concentrations of Zn, Fe, Cu and As were in the range of 0.004 - 0.330 mg L-1. Iron was the most deposited metal in sediment samples in contrast to water samples where all investigated metals were detected. For the purpose of heavy metals determination in fresh fish tissue, fifteen samples of three different fish species, silver carp (Hypophthalmichthys molitrix), common carp (Cyprinus carpio) and wels catfish (Silurus glanis) were collected. Concentrations of Pb, Cd, As and Hg were determined in the digestive tract, liver and muscle by absorption spectroscopy. The highest concentration of Pb was in the digestive tract in all three fish species, ranging from 0.036 to 1.518 μg g-1, while Cd was mostly deposited in the liver. Concentrations of As were in the range of 0.36 - 0.73 μg g-1 in Hypophthalmichthys molitrix, 0.013 - 0.18 μg g-1 in Cyprinus carpio and 0.003 - 0.005 μg g-1 in Silurus glanis tissues, while the content of Hg was equal in all tested tissues of carp. Concentrations of all metals were found to be present in the fish samples at different levels, but these values are under the maximum residual levels prescribed by the European Union (EU) and the maximum allowed concentrations (MAC) for Serbia, so the fish meat is acceptable for the human consumption.

Antibacterial efficacy and pharmacokinetic evaluation of sanguinarine in common carp (Cyprinus carpio) following a single intraperitoneal administration

Sanguinarine (SA), with antimicrobial and antiparasitic activities against fish pathogens, exhibits great potential commercial use in aquaculture. However, little information on pharmacokinetics of SA restricts further application in aquaculture. In this study, pharmacokinetics of SA in common carp (Cyprinus carpio) following a single intraperitoneal administration [10mgkg(-1) BW (body weight)] was evaluated by high-performance liquid chromatography (HPLC). The peak concentration (Cmax ) of SA in kidney was 11.8μgg(-1) , which was higher than in other tissues and plasma. The terminal half-life in fish tissue and plasma was as follows: 42.3h (kidney)>37.2h (liver)>20.1h (gill)>18.8h (muscle)>10.9h (spleen)>10.0h (plasma). Additionally, we determined the bacterial loads in tissues of common carp infected with Aeromonas hydrophila after i.p. administration of SA at 0, 5, 10 and 20mgkg(-1) BW. The results showed that i.p. administration of SA at 10mgkg(-1) BW significantly enhanced antibacterial efficacy against A.hydrophila, where the antibacterial ratio in the gill, kidney, spleen and liver on day 5 was 95.13%, 93.33%, 90.09% and92.82%, respectively. Overall, these results suggested the potential of SA to treat A.hydrophila infection in common carp farming industry.

Free amino acid content in muscle tissue of bighead carp and wels catfish

The present research was aimed at a comparative analysis of free amino acid (FAA) levels in the muscle tissue of herbivorous and predatory fish. The FAA concentration in the muscle tissue samples from bighead carp and wels catfish was determined by ion-exchange chromatography. The bighead carp muscle tissue, as compared to that of wels catfish, showed significantly higher concentrations of arginine, histidine, methionine, phenyloalanine, alanine, asparagine, serine, glycine, and taurine, but significantly lower levels of isoleucine, leucine, threonine, valine, glutamine, cystationine, β-alanine, ethanoloamine, as well as aspartic, glutamic, cysteic, α- and γ-aminobutyric acids. The muscle tissues of bighead carp and wels catfish did not differ significantly in the levels of cystine, lysine, tryptophan, tyrosine, α-aminoadipic acid, cytrulline, ornithine and 1-methyl-histidine. Proline was detected only in the wels catfish muscle. The results obtained have shown differences in free amino acid concentration in muscle tissue of examined fish. A differentiated natural diet induces changes in free amino acid content in fish tissues. Knowledge of levels of free amino acids which are precursors for biogenic amines facilitates setting the safety criteria for fish and fishery products from species other than those mentioned in the Commission Regulation No 2073/2005

Grass carp Ctenopharyngodon idella Fibulin-4 as a potential interacting partner for grass carp reovirus outer capsid proteins.

Mammalian EGF containing fibulin-like extracellular matrix protein 2 (Fibulin-4/EFEMP2), an extracellular matrix(ECM) protein and a member of the fibulin family, is involved in elastic fiber formation, connective tissue development and some human diseases. In a yeast-two hybrid screening of host proteins interacting with outer capsid protein of grass carp reovirus (GCRV), a grass carp homologue of Fibulin-4 (designated as GcFibulin-4) is suggested to hold the potential to bind VP7, VP56 and VP55, the outer capsid protein encoded by type I, II, III GCRV, respectively. GcFibulin-4 gene of grass carp was cloned and sequenced from the cDNA library constructed for the yeast two-hybrid screening. Full-length cDNA of GcFibulin-4 contains an open reading frame (ORF) of 1323 bp encoding a putative protein of 440 amino acids. Phylogenetic analysis of GcFibulin-4 indicated that it shared a high homology with zebra fish Fibulin-4 protein. Transcriptional distribution analysis of GcFibulin-4 in various tissues of healthy grass carp showed that GcFibulin-4 was highly expressed in muscle, moderately expressed in the intestine and brain, and slightly expressed in other examined tissues; the expression pattern is consistent with tissue tropism of GCRV resulting in hemorrhage symptom in the corresponding tissues. Our results suggested that Fibulin-4 might enable free GCRV particles, the pathogen for grass carp hemorrhagic disease, to target fish tissues more efficiently by interacting with viral outer capsid proteins.