27 resultados para Piscine


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The use of synthetic and non-synthetic hormones have been reported in different regions with the recommendation of different doses. The adaptability of these findings have however not been very successful due to the high cost of building and maintaining hatchery, high cost of synthetic hormone (when available) and high level manpower required. It is obvious that adaptive research in the past ten years in developing countries like Nigeria have been geared towards utilization of resources that are equally effective but cheap and ready to come by. This paper reports the utilization of the pituitary extract of bull frog (Rana adspersa) and the toad (Bufo regularis) in the induced breeding of the African catfish, Clarias gariepinus. The extraction and dosage are discussed alongside the preliminary rearing of fries in outdoor hatchery tanks. Human chorionic gonadotrophin (HCG) and Clarias pituitary extracts were used as control

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La désinfection de l’eau de consommation et des piscines induit la formation de sous-produits (SPD) potentiellement nocifs pour la santé, parmi lesquels les trihalométhanes (THM), les acides haloacétiques (HAA) et les chloramines (CAM). La difficulté d’estimer l’exposition humaine à ces SPD empêche de cerner précisément les risques sanitaires possiblement associés (i.e., cancérigènes, reprotoxiques, irritatifs). Nos travaux s’articulent autour d’une méthodologie consistant à intégrer des données d’occurrence environnementales à des modèles toxicocinétiques à base physiologique (TCBP) pour améliorer les mesures de l’exposition aux SPD. Cette approche multidisciplinaire veut prendre en compte de manière aussi appropriée que possible les deux composantes majeures des variations de cette exposition : les variations spatio-temporelles des niveaux de contamination environnementale et l’impact des différences inter- et intra-individuelles sur les niveaux biologiques. Cette thèse, organisée en deux volets qui explorent chacun successivement des aspects environnemental et biologique de la problématique, vise à contribuer au développement de cette stratégie innovante d’estimation de l’exposition et, plus généralement, à des meilleures pratiques en la matière. Le premier volet de la thèse s’intéresse à l’exposition en milieu domestique (i.e., résultant de l’utilisation de l’eau potable au domicile) et est consacré au cas complexe des THM, les plus abondants et volatils des SPD, absorbables par ingestion mais aussi par inhalation et voie percutanée. Les articles I et II, constitutifs de ce volet, documentent spécifiquement la question des variations inter- et intra- journalières de présence des SPD en réseau et de leurs impacts sur les estimateurs de l’exposition biologique. Ils décrivent l’amplitude et la diversité des variations à court terme des niveaux environnementaux, présentent les difficultés à proposer une façon systématique et « épidémiologiquement » pratique de les modéliser et proposent, de manière originale, une évaluation des mésestimations, somme toute modestes, des mesures biologiques de l’exposition résultant de leurs non-prise en compte. Le deuxième volet de la thèse se penche sur l’exposition aux SPD en piscine, d’un intérêt grandissant au niveau international, et se restreint au cas jugé prioritaire des piscines publiques intérieures. Ce volet envisage, pour quantifier l’exposition dans ce contexte particulier, l’extension de l’approche méthodologique préconisée, élaborée originellement pour application dans un contexte domestique : d’abord, à travers une analyse approfondie des variations des niveaux de contamination (eau, air) des SPD en piscine en vue de les modéliser (article III); puis en examinant, dans le cas particulier du chloroforme, le THM le plus abondant, la possibilité d’utiliser la modélisation TCBP pour simuler des expositions en piscine (article IV). Les résultats mettent notamment en évidence la difficulté d’appréhender précisément la contamination environnementale autrement que par un échantillonnage in situ tandis que la modélisation TCBP apparait, sur le plan toxicologique, comme l’outil le plus pertinent à ce jour, notamment au regard des autres approches existantes, mais qu’il convient d’améliorer pour mieux prédire les niveaux d’exposition biologique. Finalement, ces travaux illustrent la pertinence et la nécessité d’une approche multidisciplinaire et intégratrice et suggère, sur cette base, les pistes à explorer en priorité pour mieux évaluer l’exposition aux SPD et, in fine, cerner véritablement les risques sanitaires qui en résultent.

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La seguente tesi ha come scopo la progettazione e la realizzazione di un sistema intelligente per la gestione e il monitoraggio dell'acqua in impianti facenti uso di docce attraverso 'l'Internet Of Things', con l'obiettivo di ridurre gli sprechi favorendo cosi un risparmio sia di tipo energetico sia di tipo idrico. Stabiliti i requisiti si passa alla fase di progettazione dove vengono analizzate tutte le funzionalità che il sistema deve soddisfare. Segue la fase di implementazione, il cui scopo e realizzare concretamente le funzionalità producendo un prototipo iniziale. Quest'ultimo sara sottoposto ad eventuali test per verificare il corretto funzionamento del sistema e delle singole parti che lo costituiscono.

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The Chondrichthyes (cartilaginous fishes) are commonly accepted as being sister group to the other extant Gnathostomata (jawed vertebrates). To clarify gnathostome relationships and to aid in resolving and dating the major piscine divergences, we have sequenced the complete mtDNA of the starry skate and have included it in phylogenetic analysis along with three squalomorph chondrichthyans—the common dogfish, the spiny dogfish, and the star spotted dogfish—and a number of bony fishes and amniotes. The direction of evolution within the gnathostome tree was established by rooting it with the most closely related non-gnathostome outgroup, the sea lamprey, as well as with some more distantly related taxa. The analyses placed the chondrichthyans in a terminal position in the piscine tree. These findings, which also suggest that the origin of the amniote lineage is older than the age of the oldest extant bony fishes (the lungfishes), challenge the evolutionary direction of several morphological characters that have been used in reconstructing gnathostome relationships. Applying as a calibration point the age of the oldest lungfish fossils, 400 million years, the molecular estimate placed the squalomorph/batomorph divergence at ≈190 million years before present. This dating is consistent with the occurrence of the earliest batomorph (skates and rays) fossils in the paleontological record. The split between gnathostome fishes and the amniote lineage was dated at ≈420 million years before present.

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Dissertação de mestrado, Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2014

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Chlamydial infections of fish are emerging as an important cause of disease in new and established aquaculture industries. To date, epitheliocystis, a skin and gill disease associated with infection by these obligate intracellular pathogens, has been described in over 90 fish species, including hosts from marine and fresh water environments. Aided by advances in molecular detection and typing, recent years have seen an explosion in the description of these epitheliocystis-related chlamydial pathogens of fish, significantly broadening our knowledge of the genetic diversity of the order Chlamydiales. Remarkably, in most cases, it seems that each new piscine host studied has revealed the presence of a phylogenetically unique and novel chlamydial pathogen, providing researchers with a fascinating opportunity to understand the origin, evolution and adaptation of their traditional terrestrial chlamydial relatives. Despite the advances in this area, much still needs to be learnt about the epidemiology of chlamydial infections in fish if these pathogens are to be controlled in farmed environments. The lack of in vitro methods for culturing of chlamydial pathogens of fish is a major hindrance to this field. This review provides an update on our current knowledge of the taxonomy and diversity of chlamydial pathogens of fish, discusses the impact of these infections on the health, and highlights further areas of research required to understand the biology and epidemiology of this important emerging group of fish pathogens of aquaculture species.

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Experiment on induced spawning of Clarias lazera and C. anguillaris using human chorionic gonadotropin (HCG) freshly prepared toad and Clarias pituitary hormogenates were carried out. Clarias pituitary hormogenates induced spawning in C. lazera and C. anguillaris at dosage levels of 0.27-0.46 mg/150 g body weight or 2 glands/fish of equivalent weights. HCG induced spawning in C. anguillaris at 500 i.u/500 g body weight but failed in C. lazera. Toad pituitary was not successful at even a higher dosage level of 0.60 mg/150 g body weight. The implications of these results are discussed. Spawning occurred in the HCG (and Clarias pituitary treated females in less than 12 hours after injection and subsequent examination of ovaries of the spawned fish showed incomplete spawning. Furthermore, fertilization occurred, following spawning in the piscine pituitary hormone treated male and female fish but failed in the HCG (treated pair. A mean fertilization rate of 50-90% was recorded. Possible explanations of these observations are advanced. The hatching time of 24-48 hours and a mean hatching rate of 75-90% were recorded. A high larval mortality of up to 95% was observed in the post yolk-sac stag after 8 days. The need for the development of appropriate larval food for Clarias species in culture practice is stressed

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In the interferon-induced antiviral mechanisms, the Mx pathway is one of the most powerful. Mx proteins have direct antiviral activity and inhibit a wide range of viruses by blocking an early stage of the viral genome replication cycle. However, antiviral activity of piscine Mx remains unclear in vivo. In the present study, an Mx-like gene was cloned, characterized and gene-transferred in rare minnow Gobiocypris rarus, and its antiviral activity was confirmed in vivo. The full length of the rare minnow Mx-like cDNA is 2241 bp in length and encodes a polypeptide of 625 amino acids with an estimated molecular mass of 70.928 kDa and a predicted isoelectric point of 7.33. Analysis of the deduced amino acid sequence indicated that the mature peptide contains an amino-terminal tripartite GTP-binding motif, a dynamin family signature sequence, a GTPase effector domain and two carboxy-terminal leucine zipper motifs, and is the most similar to the crucian carp (Carassius auratus) Mx3 sequence with an identity of 89%. Both P0 and F1 generations of Mx-transgenic rare minnow demonstrated very significantly high survival rate to GCRV infection (P < 0.01). The mRNA expression of Mx gene was consistent with survival rate in F1 generation. The virus yield was also concurrent with survival time using electron microscope technology. Rare minnow has Mx gene(s) of its own but introducing more Mx gene improves their resistance to GCRV. Mx-transgenic rare minnow might contribute to control the GCRV diseases. (C) 2008 Published by Elsevier Ltd.

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Rainbow trout historic H3 (RH3) promoter was cloned via high fidelity PCR. The cloned RH3 promoter was inserted into a promoter-lacked vector pEGFP-1, resulting in an expression vector pRH3FGFP-1. The linearized pRH3EGFP-1 was microinjected into fertilized eggs of rare minnows and the sequential embryogenetic processes were monitored under a fluorescent microscope. Strong green fluorescence was ubiquitously observed at as early as the gastrula stage and then in various tissues at the fry stage. The results indicate that RH3 promoter, as a piscine promoter, could serve in producing transgenic Cyprinoid such as rare minnow. Promoter activity of RH3, CMV and common carp beta-actin (CA) were compared in rare minnow by the expression of respective recombinant EGFP vectors. The expression of pCMVEGFP occurred earlier than the following one, pRH3EGFP-1, and then pCAEGFP during the embryogenesis of the transgenics. Their expression activities demonstrated that the CMV promoter is the strongest one, followed by the CA and then the RH3.

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The interleukin 1beta (IL-1beta) cDNA was cloned from the red seabream (Pagrus major) by homology cloning strategy. A cDNA fragment was amplified by PCR using two degenerated primers, which were designed according to the conserved regions of other known IL-1beta sequences, and elongated by 3' ends and 5' ends RACE PCR to get the full length coding sequence of red seabream IL-1beta (RS IL-1beta). The sequence contained 1252 nucleotides that included a 5' untranslated region (UTR) of 84 bp, a 3' UTR of 410 bp and an open reading frame (ORF) of 759 nucleotides which could be translated into a putative peptide of 253 amino acids with molecular weight of 28.6 kD and putative isoelectric point pI of 5.29. The deduced peptide contained two potential N-glycosylation sites and an identifiable IL1 family signature, but lacked the signal peptide and the clear ICE cut site, which were common in other nonmammalian IL-1beta genes. The RS IL-1beta had the highest homology with piscine IL-1beta according to phylogenetic tree analysis. The transcript expression was detected in blood, brain, gill, heart, head kidney, kidney, liver, muscle and spleen in the pathogen challenged and healthy red seabream by RTPCR. Results showed that the RS IL-1beta mRNA was constitutively expressed in most of the tissues both in stimulated and un-stimulated fish, and the expression could be enhanced by pathogen challenging.

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A fragment of TNFalpha cDNA sequence from red seabream was cloned by homology cloning approach with two degenerated primers which were designed based on the conserved regions of other animals' TNF sequences. The sequence was elongated by 3' and 5' RACE to get the full length CDS sequence. This sequence contained 1264 nucleotides that included a 5' UTR of 85 bp, a 3' UTR of 514 bp and an open reading frame (ORF) of 666 bp which could encode 222 amino acids propeptide. In 3' UTR, there were several mRNA instability motifs and three endotoxin-responsive sequences, but the sequence lacked the polyadenylation signal. The deduced peptide had a clear transmembrane domain, a TNFalpha family signature and a TNF2 family profile. The cell attachment sequence and the glycosaminoglycan attachment sites were also found in the sequence. The red seabream TNF sequence shared relatively high similarity with both mammalian TNFalpha and TNFbeta by multiple sequence alignments. Phylogenetic analysis showed that the piscine TNFalpha were located independently in a different branch compared with mammalian TNFalpha and TNFbeta. Based on the primary and secondary structure analysis and gene expression study, we could concluded that the red seabream TNF should be a TNFalpha, not TNFbeta. RT-PCR was used to study TNFa transcript expression. 24 h after the red seabream was challenged by Vibrio anguillarum, the RS TNFalpha transcript expression were detected in blood, brain, gill, heart, head kidney, kidney, Ever, muscle and spleen. Results showed that TNFalpha mRNA was constitutively expressed in parts of the tissues both in stimulated and unstimulated fish and the expression could be enhanced after the pathogen infection.

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ISG15 is an interferon-stimulated gene that encodes a ubiquitin-like protein. ISG15 homologues have been identified in a number of fish species, some of which are known to be regulated at expression level by virus infection and lipopolysacchande (LPS) treatment However, the relationship between ISG15 and live bacterial infection has not been investigated in piscine models. In this study, an ISG15 homologue, SoISG15, was identified from red drum Scraeriops ocellaws and analyzed at expression and functional levels The open reading frame ofSolSG15 is 477 base pairs (bp) and mtronless, with a 5'-untranslated region (UTR) of 91 bp and a 3'-UTR of 415 bp The deduced amino acid sequence of S0ISG15 shares 60-67% overall identities with the ISG15 of several fish species. S0ISG15 possesses two conserved ubiquinn-like domains and the canonical ubiquitin conjugation motif, LRGG, at the C-terminus. Expressional analysis showed that constitutive expression of SolSG15 was highest in blood and lowest in kidney Experimental challenges with LPS and bacterial pathogens induced significant S0ISG15 expression in the kidney but not in the liver Similar differential induction was also observed at cellular level with primary hepatocytes and head kidney (HK) lymphocytes. Poly(' C), however, effected drastic induction of S0ISG15 expression in kidney and liver at both tissue and cellular levels. Immunoblot analysis showed that S0ISG15 was secreted by cultured HK lymphocytes into the extracellular milieu. Recombinant S0ISG15 expressed in and purified from Eschenclua colt was able to enhance the respiratory burst activity, acid phosphatase activity, and bactericidal activity of HK macrophages. Taken together, the results of this study indicated that SoISG 15 possesses apparent immunological property and is likely to be involved in host immune defense against bacterial infection. (C)2010 Elsevier Ltd All rights reserved.

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The production and puriWcation of gilthead sea bream recombinant parathyroid hormone related protein [sbPTHrP(1–125)] using an Escherichia coli system and one step puriWcation process with continuous elution gel electrophoresis is reported. The cDNA encoding sbPTHrP(1–125) was cloned into a prokaryotic expression vector pET-11a. The recombinant plasmid was used to transfect E. coli BL21(DE3) pLysS and sbPTHrP(1–125) synthesis was induced by addition of 1mM isopropyl- -D-thiogalactopyranoside. The rapid one step isolation method gave pure sbPTHrP(1–125) as judged by SDS–PAGE and yielded up to 40mg/L of culture medium (3.3mg protein/g of bacteria). The bioactivity of recombinant sbPTHrP(1–125) assessed using an in vitro scale bioassay was found to be equipotent to PTHrP(1–34) in stimulating cAMP accumulation. Assessment of the immunological reactivity of the isolated protein by Western blot revealed it cross-reacts with antisera speciWc for the N-terminal and C-terminal region of PTHrP. In a radioimmunoassay speciWc for piscine N-terminal (1–34 aa) PTHrP, the recombinant sbPTHrP(1–125) was equipotent with PTHrP(1–34) in displacing labelled 125I-PTHrP(1–36) PTHrP from the antisera. The availability of recombinant sbPTHrP will allow the development of region speciWc assays and studies aimed at deWning post-secretory processing of this protein and its biological activity in Wsh.

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Whole animal studies have indicated that Ca2+ uptake by the gastrointestinal tract is regulated by the action of parathyroid hormone-related peptide (PTHrP) in teleost fish. We have characterised PTH receptors (PTHR) in piscine enterocytes and established, by using aminoterminal PTHrP peptides, the amino acid residues important for receptor activation and for stabilising the ligand/receptor complex. Ligand binding of 125I-(1–35tyr) PTHrP to the membrane fraction of isolated sea bream enterocytes revealed the existence of a single saturable high-affinity receptor (KD=2.59 nM; Bmax=71 fmol/mg protein). Reverse transcription/polymerase chain reaction with specific primers for sea bream PTH1R and PTH3R confirmed the mRNA expression of only the later receptor. Fugu (1–34) PTHrP increased cAMP levels in enterocytes but had no effect on total inositol phosphate accumulation. The aminoterminal peptides (2–34)PTHrP, (3–34)PTHrP and (7–34) PTHrP bound efficiently to the receptor but were severely defective in stimulating cAMP in enterocyte cells indicating that the first six residues of piscine (1–34)PTHrP, although not important for receptor binding, are essential for activation of the adenylate cyclase/phosphokinase A (AC-PKA)-receptor-coupled intracellular signalling pathway. Therefore, PTHrP in teleosts acts on the gastrointestinal tract through PTH3R and the AC-PKA intracellular signalling pathway and might regulate Ca2+ uptake at this site. Ligand-receptor binding and activity throughout the vertebrates appears to be allocated to the same amino acid residues of the amino-terminal domain of the PTHrP molecule.

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Travail d'intégration présenté à Isabelle Gagnon dans le cadre du cours PHT-6113.