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Kenneth B Storey - One of the best experts on this subject based on the ideXlab platform.
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Purification and Regulation of Pyruvate Kinase from the Foot Muscle of the Anoxia and Freeze Tolerant Marine Snail, Littorina littorea
The Protein Journal, 2020Co-Authors: Michael B. Smolinski, Anchal Varma, Stuart R. Green, Kenneth B StoreyAbstract:The intertidal marine snail, Littorina littorea , has evolved to survive bouts of anoxia and extracellular freezing brought about by changing tides and subsequent exposure to harsh environmental conditions. Survival in these anoxic conditions depends on the animals entering a state of metabolic rate depression in order to maintain an appropriate energy production-consumption balance during periods of limited oxygen availability. This study investigated the kinetic, physical, and regulatory properties of pyruvate kinase (PK), which catalyzes the final reaction of aerobic glycolysis, from Foot Muscle of L. littorea to determine if the enzyme is differentially regulated in response to anoxia and freezing exposure. PK purified from Foot Muscle of anoxic animals exhibited a lower affinity for its substrate phosphoenolpyruvate than PK from control and frozen animals. PK from anoxic animals was also more sensitive to a number of allosteric regulators, including alanine and aspartate, which are key anaerobic metabolites in L. littorea . Furthermore, PK purified from anoxic and frozen animals exhibited greater stability compared to the non-stressed control animals, determined through high-temperature incubation studies. Phosphorylation of threonine and tyrosine residues was also assessed and demonstrated that levels of threonine phosphorylation of PK from anoxic animals were significantly higher than those of PK from control and frozen animals, suggesting a potential mechanism for regulating PK activity. Taken together, these results suggest that PK plays a role in suppressing metabolic rate in these animals during environmental anoxia exposure.
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estivation responsive micrornas in a hypometabolic terrestrial snail
PeerJ, 2019Co-Authors: Myriam P Hoyeck, Hanane Hadjmoussa, Kenneth B StoreyAbstract:When faced with extreme environmental conditions, the milk snail (Otala lactea) enters a state of dormancy known as estivation. This is characterized by a strong reduction in metabolic rate to <30% of normal resting rate that is facilitated by various behavioural, physiological, and molecular mechanisms. Herein, we investigated the regulation of microRNA in the induction of estivation. Changes in the expression levels of 75 highly conserved microRNAs were analysed in snail Foot Muscle, of which 26 were significantly upregulated during estivation compared with controls. These estivation-responsive microRNAs were linked to cell functions that are crucial for long-term survival in a hypometabolic state including anti-apoptosis, cell-cycle arrest, and maintenance of Muscle functionality. Several of the microRNA responses by snail Foot Muscle also characterize hypometabolism in other species and support the existence of a conserved suite of miRNA responses that regulate environmental stress responsive metabolic rate depression across phylogeny.
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hexokinase regulation in the hepatopancreas and Foot Muscle of the anoxia tolerant marine mollusc littorina littorea
Comparative Biochemistry and Physiology B, 2013Co-Authors: Judeh L Lama, Ryan A V Bell, Kenneth B StoreyAbstract:Hexokinase from the hepatopancreas and Foot Muscle of Littorina littorea undergoes stable modification of its kinetic and structural properties in response to prolonged oxygen deprivation. In the hepatopancreas, a reduction in the Km glucose for hexokinase from the anoxic animal suggests a more active enzyme form during anoxia. Conversely, in the Foot Muscle, an increase in Km ATP and a decrease in Vmax for anoxic snail hexokinase were consistent with a less active enzyme form during anoxia. In either case, the molecular basis for the stable modification of hexokinase kinetics is reversible phosphorylation. The activation of endogenous PKC and AMPK increased the Km glucose for anoxic hepatopancreas hexokinase to a value that was similar to the control Km glucose. Alternatively, stimulation of endogenous PKA, PKG, and CamK for control Foot Muscle hexokinase increased the Km ATP to a value similar to that seen for the anoxic enzyme form. In both tissues, activation of endogenous phosphatases reversed the effects of protein kinases. Dephosphorylation and activation of hepatopancreas hexokinase during anoxia may allow for increased shunting of glucose-6-phosphate into the pentose phosphate pathway, thereby producing reducing equivalents of NADPH needed for antioxidant defense upon tissue re-oxygenation. Conversely, phosphorylation and inhibition of Foot Muscle hexokinase during anoxia may reflect the decreased need for glucose oxidation during hypometabolism.
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metabolic mechanisms for anoxia tolerance and freezing survival in the intertidal gastropod littorina littorea
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2013Co-Authors: Kenneth B Storey, Benjamin Lant, Obiajulu O Anozie, Janet M StoreyAbstract:The gastropod mollusk, Littorina littorea L., is a common inhabitant of the intertidal zone along rocky coastlines of the north Atlantic. This species has well-developed anoxia tolerance and freeze tolerance and is extensively used as a model for exploring the biochemical adaptations that support these tolerances as well as for toxicological studies aimed at identifying effective biomarkers of aquatic pollution. This article highlights our current understanding of the molecular mechanisms involved in anaerobiosis and freezing survival of periwinkles, particularly with respect to anoxia-induced metabolic rate depression. Analysis of Foot Muscle and hepatopancreas metabolism includes anoxia-responsive changes in enzyme regulation, signal transduction, gene expression, post-transcriptional regulation of mRNA, control of translation, and cytoprotective strategies including chaperones and antioxidant defenses. New studies describe the regulation of glucose-6-phosphate dehydrogenase by reversible protein phosphorylation, the role of microRNAs in suppressing mRNA translation in the hypometabolic state, modulation of glutathione S-transferase isozyme patterns, and the regulation of the unfolded protein response.
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doi:10.1155/2012/317314 Research Article Insights into the In Vivo Regulation of Glutamate Dehydrogenase from the Foot Muscle of an Estivating Land Snail
2012Co-Authors: Ryan A V Bell, Neal J. Dawson, Kenneth B StoreyAbstract:Copyright © 2012 Ryan A. V. Bell et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Land snails, Otala lactea, survive in seasonally hot and dry environments by entering a state of aerobic torpor called estivation. During estivation, snails must prevent excessive dehydration and reorganize metabolic fuel use so as to endure prolonged periods without food. Glutamate dehydrogenase (GDH) was hypothesized to play a key role during estivation as it shuttles amino acid carbon skeletons into the Krebs cycle for energy production and is very important to urea biosynthesis (a key molecule used for water retention). Analysis of purified Foot Muscle GDH from control and estivating conditions revealed that estivated GDH was approximately 3-fold more active in catalyzing glutamate deamination as compared to control. This kinetic difference appears to be regulated by reversible protein phosphorylation, as indicated by ProQ Diamond phosphoprotein staining and incubations that stimulate endogenous protein kinases and phosphatases. The increased activity of the high-phosphate form of GDH seen in the estivating land snail Foot Muscle correlates well with the increased use of amino acids for energy and increased synthesis of urea for water retention during prolonged estivation. 1
Ronald S Tjeerdema - One of the best experts on this subject based on the ideXlab platform.
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efficacy tissue distribution and residue depletion of oxytetracycline in ws rlp infected california red abalone haliotis rufescens
Aquaculture, 2008Co-Authors: Eric S Rosenblum, Ronald S Tjeerdema, James D. Moore, Thea T Robbins, B B Scott, S Nelson, C Juhasz, A Craigmill, Carolyn S FriedmanAbstract:Abstract Oxytetracycline (OTC) was recently demonstrated to be an effective therapeutant for California red abalone ( Haliotis rufescens ) infected with the agent of withering syndrome (WS), a Rickettsia-like prokaryote (WS-RLP). This study examined the influence of temperature on the efficacy and pharmacokinetics of oral OTC treatments on WS-RLP infected red abalone, H. rufescens . Medication was administered in an artificial diet containing 1.85% active OTC at a rate of 103.4 mg/kg abalone for 10, 20 and 30 days at both 13.4 °C and 17.3 °C. Drug residue concentrations, WS-RLP burden and WS-associated pathological changes within Foot Muscle and digestive gland were measured 3, 17, 23, 42, 63, 81, 102, 122, and 160 days after OTC treatment. In all samples the highest concentrations of OTC were detected on the first sample day. Furthermore, all sampling periods showed significantly less OTC in Foot Muscle samples relative to corresponding digestive gland samples ( p p
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characterizing the metabolic actions of natural stresses in the california red abalone haliotis rufescens using 1 h nmr metabolomics
Metabolomics, 2005Co-Authors: Eric S Rosenblum, James D. Moore, Carolyn S Friedman, Mark R Viant, B M Braid, Ronald S TjeerdemaAbstract:Withering syndrome in California red abalone (Haliotis rufescens) is caused by the Rickettsiales-like prokaryote (WS-RLP) Candidatus Xenohaliotis californiensis. WS-RLP infection is not sufficient to cause withering syndrome, and for reasons not yet well understood additional stressors such as elevated water temperature appear to influence disease development. Using nuclear magnetic resonance (NMR) based metabolomics, we have investigated the influence of food availability, temperature, and bacterial infection, both individually and in combination, on the metabolic status of the red abalone. Food limitation caused dramatic reductions in all observed classes of Foot Muscle metabolites, while at the same time metabolite levels within the digestive gland were preserved or increased. We also found that food limitation in combination with elevated temperature led to greater metabolic perturbations in both tissue types than those observed under food limitation alone. WS-RLP infection and food-limitation resulted in many of the same metabolic changes within the tissues studied, although the effects of infection were less severe. We observed increased levels of homarine in the digestive gland of both food-limited and WS-RLP-infected animals, yet only observed increased homarine levels in the Foot Muscle of infected abalone. These results further support the recently established glucose-to-homarine ratio in Foot Muscle as a potential marker for differentiating WS-RLP-infected animals from those of both healthy and food limited abalone. Furthermore, we found that the NMR metabolic data correlates well with histological measurements supporting the use of the metabolomics approach for characterizing both normal and pathological events in marine species, particularly during periods of environmentally relevant stress.
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nmr based metabolomics a powerful approach for characterizing the effects of environmental stressors on organism health
Environmental Science & Technology, 2003Co-Authors: Mark R Viant, Eric S Rosenblum, Ronald S TjeerdemaAbstract:It is important to assess the chronic effects of chemical, physical, and biological stressors on organisms in the environment. Appropriate methods must enable rapid, inexpensive, and multibiomarker analyses of organism health. Here we investigate withering syndrome in red abalone (Haliotis rufescens), an important wild and farmed shellfish species along the Pacific coast, using a metabolomic approach that combines the metabolic profiling capabilities of nuclear magnetic resonance spectroscopy (NMR) with pattern recognition methods. Foot Muscle, digestive gland, and hemolymph samples were collected from healthy, stunted, and diseased abalone, and the extracts were analyzed by NMR. Following spectral preprocessing, principal components analyses of the metabolite profiles were conducted. Our results confirm that NMR-based metabolomics can successfully distinguish the biochemical profiles of the three groups of animals, in every type of tissue or biofluid studied. Furthermore, this discovery-based approach su...
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sublethal actions of copper in abalone haliotis rufescens as characterized by in vivo 31p nmr
Aquatic Toxicology, 2002Co-Authors: Mark R Viant, Jeffrey H Walton, Patti L Tenbrook, Ronald S TjeerdemaAbstract:Abstract The sublethal biochemical actions of copper in live, intact red abalone ( Haliotis rufescens ) were characterized by in vivo 31 P nuclear magnetic resonance spectroscopy (NMR). This non-invasive technique is ideal for examining cellular respiration since critical metabolite concentrations, including phosphoarginine ([PA]), inorganic phosphate ([P i ]) and [ATP], and the arginine kinase (AK) rate constant, can be monitored in real time. Both metabolite concentrations and enzyme rate constants were measured in abalone during 8-h exposures to 66 μg l −1 (1.04 μM) and 126 μg l −1 (1.98 μM) copper (as CuCl 2 ). Significant decreases in [PA] and corresponding increases in [P i ] resulted, while [ATP] remained constant. In controls [PA], [P i ] and [ATP] all remained unchanged. Furthermore, both copper concentrations induced a significant elevation in the forward AK rate constant over the basal value of 0.020±0.002 s −1 . Metabolite levels and enzyme rate constants were also measured during 8-h 66 μg l −1 copper exposures both before and after a 2-week subchronic exposure to 36 μg l −1 (0.57 μM) copper. Unlike before the subchronic exposure, no significant changes in [PA], [P i ] or [ATP] were observed after the 36 μg l −1 copper treatment, compared with controls. This induced tolerance was also evident from the forward AK rate constant data. Finally, copper accumulation was determined in gill, digestive gland and Foot Muscle samples. Whereas acute exposure only led to significant accumulation in the gill, copper levels in subchronically exposed abalone were significantly elevated in both the gill and digestive gland, and marginally so in Foot Muscle. Overall, the gill appears to be the primary site of copper accumulation and toxicity, while the Foot and adductor Muscles maybe secondarily impacted. The observed metabolic changes may result from insufficient oxygen delivery to the Muscles, resulting from mucus accumulation or cytological damage at the gill. In conclusion, abalone acutely exposed to copper pollution may develop asphyxial hypoxia. Since their survival is dependent on adherence to rock surfaces, such a reduction of Muscle function could ultimately prove fatal.
Antonio Figueras - One of the best experts on this subject based on the ideXlab platform.
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candidatus xenohaliotis californiensis and haplosporidium montforti associated with mortalities of abalone haliotis tuberculata cultured in europe
Aquaculture, 2006Co-Authors: Pablo Balseiro, C Gestal, Beatriz Novoa, Raquel Aranguren, Antonio FiguerasAbstract:Haliotis tuberculata experimentally grown in Galicia (NW Spain) and originated from Ireland began to experience mortalities during the late spring of 2004. Diseased abalone presented dark Foot pigmentation, loss of surface adherence and limited ability for right themselves after they were set on their backs. Histopathological analyses showed the presence of Candidatus Xenohaliotis californiensis, a bacterial pathogen from the family Rickettsiaceae, in the gastrointestinal epithelial cells of diseased abalone. To our knowledge, this is the first report of Candidatus Xenohaliotis californiensis in H. tuberculata cultured in Europe. The presence of several stages of development of a new protozoan parasite belonging to the phylum Haplosporidia, Haplosporidium montforti, described by us in a separate paper, was also detected in the connective tissue of gill, digestive gland and Foot Muscle. Complete mortality (100% of the stock) was reached during spring and summer. PCR analyses showed that these two pathogens were already present in juveniles from Ireland before their introduction in Galician waters. Juveniles imported from France were also infected with both pathogens. In adult abalone collected from natural beds of the surroundings of the aquaculture facilities, only the pathogen Candidatus Xenohaliotis californiensis was detected by PCR, but not by histology.
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candidatus xenohaliotis californiensis and haplosporidium montforti associated with mortalities of abalone haliotis tuberculata cultured in europe
Aquaculture, 2006Co-Authors: Pablo Balseiro, C Gestal, Beatriz Novoa, Raquel Aranguren, Antonio FiguerasAbstract:Haliotis tuberculata experimentally grown in Galicia (NW Spain) and originated from Ireland began to experience mortalities during the late spring of 2004. Diseased abalone presented dark Foot pigmentation, loss of surface adherence and limited ability for right themselves after they were set on their backs. Histopathological analyses showed the presence of Candidatus Xenohaliotis californiensis, a bacterial pathogen from the family Rickettsiaceae, in the gastrointestinal epithelial cells of diseased abalone. To our knowledge, this is the first report of Candidatus Xenohaliotis californiensis in H. tuberculata cultured in Europe. The presence of several stages of development of a new protozoan parasite belonging to the phylum Haplosporidia, Haplosporidium montforti, described by us in a separate paper, was also detected in the connective tissue of gill, digestive gland and Foot Muscle. Complete mortality (100% of the stock) was reached during spring and summer. PCR analyses showed that these two pathogens were already present in juveniles from Ireland before their introduction in Galician waters. Juveniles imported from France were also infected with both pathogens. In adult abalone collected from natural beds of the surroundings of the aquaculture facilities, only the pathogen Candidatus Xenohaliotis californiensis was detected by PCR, but not by histology.
Shit F Chew - One of the best experts on this subject based on the ideXlab platform.
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using glutamine synthetase 1 to evaluate the symbionts potential of ammonia assimilation and their responses to illumination in five organs of the giant clam tridacna squamosa
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2021Co-Authors: Leanne S X Teh, Mel V Boo, Jeslyn Shi Ting Poo, Shit F ChewAbstract:Abstract Nitrogen-deficient symbiotic dinoflagellates (zooxanthellae) living inside the fluted giant clam, Tridacna squamosa, need to obtain nitrogen from the host. Glutamine synthetase 1 (GS1) is a cytosolic enzyme that assimilates ammonia into glutamine. We determined the transcript levels of zooxanthellal GS1 (Zoox-GS1), which represented comprehensively GS1 transcripts of Symbiodinium, Cladocopium and Durusdinium, in five organs of T. squamosa. The outer mantle had significantly higher transcript level of Zoox-GS1 than the inner mantle, Foot Muscle, hepatopancreas and ctenidium, but the transcript ratios of Zoox-GS1 to zooxanthellal form II ribulose-1,5-bisphosphate carboxylase/oxygenase (Zoox-rbcII), which represented the potential of ammonia assimilation relative to the phototrophic potential, were comparable among these five organs. Based on transcript ratios of Zoox-GS1 to zooxanthellal Urease (Zoox-URE), the outer mantle had the highest potential of urea degradation relative to ammonia assimilation among the five organs, probably because urea degradation could furnish CO2 and NH3 for photosynthesis and amino acid synthesis, respectively, in the symbionts therein. The protein abundance of Zoox-GS1 was upregulated in the outer mantle and the inner mantle during illumination. Zoox-GS1 could catalyze light-enhanced glutamine formation using ammonia absorbed from the host or ammonia released through urea degradation in the cytoplasm. The glutamine produced could be used to synthesize other nitrogenous compounds, including amino acids in the cytoplasm or in the plastid of the dinoflagellates. Some of the amino acids synthesized by the symbionts in the inner mantle and Foot Muscle could be donated to the host to support shell organic matrix formation and Muscle production, respectively.
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symbiodiniaceae dinoflagellates express urease in three subcellular compartments and upregulate its expression levels in situ in three organs of a giant clam tridacna squamosa during illumination
Journal of Phycology, 2020Co-Authors: Germaine Ching Yun Teng, Kum C Hiong, Jeslyn Shi Ting Poo, Mel V Boo, Wai P Wong, Hyoju Kim, Shit F ChewAbstract:Giant clams harbor three genera of symbiotic dinoflagellates (Symbiodinium, Cladocopium, and Durusdinium) as extracellular symbionts (zooxanthellae). While symbiotic dinoflagellates can synthesize amino acids to benefit the host, they are nitrogen-deficient. Hence, the host must supply them with nitrogen including urea, which can be degraded to ammonia and carbon dioxide by urease (URE). Here, we report three complete coding cDNA sequences of URE, one for each genus of dinoflagellate, obtained from the colorful outer mantle of the giant clam, Tridacna squamosa. The outer mantle had higher transcript level of Tridacna squamosa zooxanthellae URE (TSZURE) than the whitish inner mantle, Foot Muscle, hepatopancreas, and ctenidium. TSZURE was immunolocalized strongly and atypically in the plastid, moderately in the cytoplasm, and weakly in the cell wall and plasma membrane of symbiotic dinoflagellates. In the outer mantle, illumination upregulated the protein abundance of TSZURE, which could enhance urea degradation in photosynthesizing dinoflagellates. The urea-nitrogen released could then augment synthesis of amino acids to be shared with the host for its general needs. Illumination also enhanced gene and protein expression levels of TSZURE/TSZURE in the inner mantle and Foot Muscle, which contain only small quantities of symbiotic dinoflagellate, have no iridocyte, and lack direct exposure to light. With low phototrophic potential, dinoflagellates in the inner mantle and Foot Muscle might need to absorb carbohydrates in order to assimilate the urea-nitrogen into amino acids. Amino acids donated by dinoflagellates to the inner mantle and the Foot Muscle could be used especially for synthesis of organic matrix needed for light-enhanced shell formation and Muscle protein, respectively.
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phototrophic potential and form ii ribulose 1 5 bisphosphate carboxylase oxygenase expression in five organs of the fluted giant clam tridacna squamosa
Coral Reefs, 2020Co-Authors: Jeslyn Shi Ting Poo, Kum C Hiong, Celine Yen Ling Choo, Mel V Boo, Wai P Wong, Shit F ChewAbstract:Despite living in oligotrophic tropical waters, giant clams can grow to large sizes because they live in symbiosis with extracellular phototrophic dinoflagellates (zooxanthellae) and receive photosynthates from them. The physical presence of zooxanthellae in five organs (colorful outer mantle, whitish inner mantle, ctenidium, hepatopancreas and Foot Muscle) of Tridacna squamosa had been confirmed by microscopy, and high densities of zooxanthellae were detected in specific regions of the inner mantle and Foot Muscle. Symbiotic dinoflagellates use form II ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) to fix inorganic carbon during C3 photosynthesis. Using qPCR primers that were designed comprehensively against all known zooxanthellal form II RuBisCO gene sequences (rbcII) in existing databases, we demonstrated that the outer mantle of T. squamosa (TS) had the greatest phototrophic potential as reflected by its high zooxanthellal rbcII (TSZrbcII) transcript level, which varied among different regions of the outer mantle. The other four organs also expressed moderate levels of TSZrbcII, despite the lack of iridophores and direct light exposure. Importantly, light exposure led to significant increases in the protein abundance of TSZRBCII in the outer mantle but not the other four organs. Taken together, these results indicate that organs inside the mantle cavity had low phototrophic potentials, but zooxanthellae residing inside these organs might serve some unidentified functions to benefit the host.
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increases in urea synthesis and the ornithine urea cycle capacity in the giant african snail achatina fulica during fasting or aestivation or after the injection with ammonium chloride
Journal of Experimental Zoology Part A: Comparative Experimental Biology, 2005Co-Authors: Kum C Hiong, Ai M Loong, Shit F ChewAbstract:The objectives of this study are to determine whether a full complement of ornithine–urea cycle (OUC) enzymes is present in the hepatopancreas of the giant African snail Achatina fulica, and to investigate whether the rate of urea synthesis and the OUC capacity can be up-regulated during 23 days of fasting or aestivation, or 24 hr post-injection with NH4Cl (10 μmol g−1 snail) into the Foot Muscle. A. fulica is ureotelic and a full complement of OUC enzymes, including carbamoyl phosphate synthetase III (CPS III), was detected from its hepatopancreas. There were significant increases in the excretion of NH4+, NH3 and urea in fasting A. fulica. Fasting had no significant effect on the tissue ammonia contents, but led to a progressive accumulation of urea, which was associated with an 18-fold increase in the rate of urea synthesis. Because fasting took place in the presence of water and because there was no change in water contents in the Foot Muscle and hepatopancreas, it can be concluded that the function of urea accumulation in fasting A. fulica was unrelated to water retention. Aestivation in arid conditions led to a non-progressive accumulation of urea in A. fulica. During the first 4 days and the last 3 days of the 23-day aestivation period, experimental snails exhibited significantly greater rates of urea synthesis compared with fasted snails. These increases were associated with significant increases in activities of various OUC enzymes, except CPS III, in the hepatopancreas. However, the overall urea accumulation in snails aestivated and snails fasted for 23 days were comparable. Therefore, the classical hypothesis that urea accumulation occurred to prevent water loss through evaporation during aestivation in terrestrial pulmonates may not be valid. Surprisingly, there were no accumulations of ammonia in the Foot Muscle and hepatopancreas of A. fulica 12 or 24 hr after NH4Cl was injected into the Foot Muscle. In contrast, the urea content in the Foot Muscle of A. fulica increased 4.5- and 33-fold at hour 12 and hour 24, respectively, and the respective increases in the hepatopancreas were 4.9- and 32-fold. The exogenous ammonia injected into A. fulica was apparently detoxified completely to urea. The urea synthesis rate increased 148-fold within the 24-hr experimental period, which could be the greatest increase known among animals. Simultaneously, there were significant increases in activities of glutamine synthetase (2.5-fold), CPS III (3.1-fold), ornithine transcarbamoylase (2.3-fold), argininosuccinate synthetase+lyase (13.6-fold) and arginase (3.5-fold) in the hepatopancreas 12 hr after the injection of NH4Cl. Taken altogether, our results support the view that the primary function of urea synthesis through the OUC in A. fulica is to defend against ammonia toxicity, but suggest that urea may have more than an excretory role in terrestrial pulmonates capable of aestivation. J. Exp. Zool. 303A:1040;–1053, 2005. © 2005 Wiley-Liss, Inc.
Christine Paillard - One of the best experts on this subject based on the ideXlab platform.
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the impacts of handling and air exposure on immune parameters gene expression and susceptibility to vibriosis of european abalone haliotis tuberculata
Fish & Shellfish Immunology, 2014Co-Authors: Marion Cardinaud, Clement Offret, Sylvain Huchette, Dario Moraga, Christine PaillardAbstract:Wild or farmed abalone are regularly exposed to stressors, such as air exposure and handling. Immune and transcriptional responses as well as susceptibility to vibriosis of sexually mature or immature European abalone acclimated at 16 or 19 °C were determined following handling or air exposure. Hemocyte density and H2O2 production increased while hemocyte viability and phagocytic index decreased following handling. Air exposure induces a decrease of hemocyte density and phagocytic index. Measurement of the expression of genes implicated in general metabolic, immunological and stress responses in gills, Foot-Muscle and hemocytes by real time q-PCR suggested that both stressors lead to a metabolic rate depression, characterized by a general inhibition of transcription. Finally, following handling a Vibrio harveyi challenge enhances almost 100% mortality of sexually immature animals at 19 °C while it has been previously demonstrated that only mature are susceptible to vibriosis.
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The impacts of handling and air exposure on immune parameters, gene expression, and susceptibility to vibriosis of European abalone Haliotis tuberculata.
Fish and Shellfish Immunology, 2014Co-Authors: Marion Cardinaud, Clement Offret, Sylvain Huchette, Dario Moraga, Christine PaillardAbstract:Wild or farmed abalone are regularly exposed to stressors, such as air exposure and handling. Immune and transcriptional responses as well as susceptibility to vibriosis of sexually mature or immature European abalone acclimated at 16 or 19 °C were determined following handling or air exposure. Hemocyte density and H2O2 production increased while hemocyte viability and phagocytic index decreased following handling. Air exposure induces a decrease of hemocyte density and phagocytic index. Measurement of the expression of genes implicated in general metabolic, immunological and stress responses in gills, Foot-Muscle and hemocytes by real time q-PCR suggested that both stressors lead to a metabolic rate depression, characterized by a general inhibition of transcription. Finally, following handling a Vibrio harveyi challenge enhances almost 100% mortality of sexually immature animals at 19 °C while it has been previously demonstrated that only mature are susceptible to vibriosis.