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Carlos Riquelme - One of the best experts on this subject based on the ideXlab platform.
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Effect of copper on the immunomodulatory activities of haemocytes in juveniles of the abalone Haliotis Rufescens cultivated under hatchery conditions
Aquaculture, 2013Co-Authors: Fernando Silva-acieres, Dario Moraga, Carlos RiquelmeAbstract:The effect of short-term exposure to copper on the cellular and physiological response in haemocytes of juvenile abalone Haliotis Rufescens cultivated in hatcheries in the north of Chile is evaluated. The animals were exposed for 168 hours to concentrations of 2.5 μg/L and 10 μg/L of Cu+ 2, which have been reported as representative of coastal zones close to mining activity, particularly copper mining. The haemocytes were collected from the animals and the effect of the metal was quantified through the total haemocyte count (THC), phagocytosis, phenoloxidase activity, and generation of superoxide anions. The results showed that copper exposure decreased THC and phagocytosis significantly, while phenoloxidase activity and superoxide anions production increased significantly with respect to untreated controls. This study suggests a relation between exposure to the trace copper concentrations and the alterations of in vitro cellular and physiological parameters of the abalone's immune system in a dose- and time-dependent manner. This study emphasize the importance of heavy metal contamination on abalone cultures considering that the haemocytes are crucial for the proper function of the immune system and important health indicators to evaluate the effect of ambient stress factors on these organisms.
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Transcriptomic and cellular response to bacterial challenge (pathogenic Vibrio parahaemolyticus) in farmed juvenile Haliotis Rufescens fed with or without probiotic diet.
Journal of Invertebrate Pathology, 2013Co-Authors: Fernando Silva-aciares, Dario Moraga, Michel Auffret, Arnaud Tanguy, Carlos RiquelmeAbstract:The abalone production in Chile has increased considerably in recent years with no sign of tapering off. Open and semi-closed circuits in the marine water zones in the north and south of Chile are the preferred areas of culture. Coastal ecosystems are subjected to a wide variety of contaminants that generate stress that affects populations via their impacts to individuals at both physiological and genetic levels. This work investigated the genomic and cellular response of post-weaning juvenile Haliotis Rufescens abalone under hatchery conditions, fed with probiotic diets, and subsequently challenged with Vibrio parahaemolyticus. The expression patterns of 16 selected genes associated with different metabolic pathways were analyzed using Real-Time PCR. Gene expression was then compared to immunological response parameters in the abalone and quantification of V. parahaemolyticus during the experimental period. Both transcriptomic and immunological analyses indicated significant alteration of physiological processes in H. Rufescens correlated to exposure to the pathogenic bacteria, as well as to probiotic nutrition.
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Effect of copper on the immunomodulatory activities of haemocytes in juveniles of the abalone Haliotis Rufescens cultivated under hatchery conditions
Aquaculture, 2013Co-Authors: Fernando Silva-aciares, Dario Moraga, Carlos RiquelmeAbstract:International audienceThe effect of short-term exposure to copper on the cellular and physiological response in haemocytes of juvenile abalone Haliotis Rufescens cultivated in hatcheries in the north of Chile is evaluated. The animals were exposed for 168 hours to concentrations of 2.5 μg/L and 10 μg/L of Cu+ 2, which have been reported as representative of coastal zones close to mining activity, particularly copper mining. The haemocytes were collected from the animals and the effect of the metal was quantified through the total haemocyte count (THC), phagocytosis, phenoloxidase activity, and generation of superoxide anions. The results showed that copper exposure decreased THC and phagocytosis significantly, while phenoloxidase activity and superoxide anions production increased significantly with respect to untreated controls. This study suggests a relation between exposure to the trace copper concentrations and the alterations of in vitro cellular and physiological parameters of the abalone's immune system in a dose- and time-dependent manner. This study emphasize the importance of heavy metal contamination on abalone cultures considering that the haemocytes are crucial for the proper function of the immune system and important health indicators to evaluate the effect of ambient stress factors on these organisms
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use of macroalgae supplemented with probiotics in the Haliotis Rufescens swainson 1822 culture in northern chile
Aquaculture Research, 2011Co-Authors: Fernando Silvaaciares, Paolo O Carvajal, Cristian Mejias, Carlos RiquelmeAbstract:In this study, we evaluate the use of macroalgae as vectors of probiotics bacteria into the digestive tract of abalone to improve their survival and growth. It is shown that when abalone Haliotis Rufescens of different sizes were fed with a natural diet composed of fronds of the macroalga Macrocystis integrifolia supplemented with a mixture of Vibrio sp. C21-UMA, Agarivorans albus F1-UMA and Vibrio sp. F15-UMA bacteria, there was a significant increase (P<0.05) in the average monthly growth rate and survival (%)in a period of 210 days, compared with the control without a probiotic supplement. The permanence of the probiotics in the digestive tract of the animals was monitored, and it was found that the number of culturable C21-UMA and F1-UMA bacteria decreased significantly (P<0.05) in recently weaned and adult abalone, and they almost disappeared completely on day 19 of the bioassay. However, the culturable Vibrio sp. F15-UMA disappeared completely from the digestive tract on day 22 of the bioassay, and these were the bacteria that remained at the highest concentration compared with the other two bacterial strains over the experimental period. It is therefore shown that it is feasible to use a probiotic mixture to improve the profitability of the H. Rufescens culture.
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Identification of genes expressed in juvenile Haliotis Rufescens in response to different copper concentrations in the north of Chile under controlled conditions
Marine Pollution Bulletin, 2011Co-Authors: Fernando Silva-aciares, Manuel Zapata, Jennifer Tournois, Dario Moraga, Carlos RiquelmeAbstract:This study reports molecular markers potentially associated with resistance or sensitivity to the impact of copper in juvenile red abalone, Haliotis Rufescens, in the north of Chile under experimental conditions. Genomic analysis was made applying subtractive hybridization libraries (SSH) to identify genes up-and down regulated during cooper exposure in abalone over periods of 12 and 168 h exposed to 2.5 and 10 μg/L of Cu+2. Results obtained from the SSH library revealed 368 different sequences regulated by copper, that correspond to eight major physiological functions. The validation of these sequences obtained by SSH as well as their expression kinetics were made by PCR in real time on 14 potential genes regulated by metal stress. This study provides information for the characterization of potential genomic markers that may be used in future environmental monitoring and to investigate new mechanisms of stress to copper in this commercially important marine species.
Cristian Gallardo-escárate - One of the best experts on this subject based on the ideXlab platform.
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Sex-related genes expression in juveniles of red abalone, Haliotis Rufescens (Swanson, 1822)
Invertebrate Reproduction & Development, 2017Co-Authors: Edgar A. López-landavery, Cristian Gallardo-escárate, Amelia Portillo-lópez, Miguel Ángel Del Río-portillaAbstract:AbstractThe red abalone, Haliotis Rufescens (Swanson 1822), is an important species for commercial aquaculture in Mexico, with annual production levels around 68 t. Not surprisingly, there is great interest in increasing production and its cultivation success. In order to have a better understanding of the genes involved in the sexual differentiation, this study analyzed the early differential expression of eight sex-related genes (VCP 2.2, VERL, VTGI, DMRT1, FP, LYS, SARIP, TEKT A1) by RT-qPCR in abalones from 5 to 45 mm of shell length. Sex identification was evaluated using VERL and LYS genes expression levels. These genes differentiated females and males from 16 mm of shell length and above. All eight sex-specific genes showed expression in all organisms. However, their level was higher in the sex group to which they correspond. In contrast, differential expression levels occurred in individuals with a shell length of 26–35 mm and 36–45 mm. These results suggest that sex gene expression is not entirel...
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RNA interference in Haliotis Rufescens myostatin evidences upregulation of insulin signaling pathway
Agri Gene, 2016Co-Authors: Crisleri Carrera-naipil, Valentina Valenzuela-muñoz, Juan Antonio Valdés, Alfredo Molina, Cristian Gallardo-escárateAbstract:Abstract Muscle growth rate is a critical issue for abalone aquaculture due to impacts on production costs. However, knowledge of the molecular mechanisms involved in molluscan myogenesis is limited. Therefore, the myostatin gene in the red abalone Haliotis Rufescens (Hr-MSTN) was characterized and evaluated at the transcriptional level using RNA interference and gene silencing correlated with the insulin pathway as a proxy for somatic growth. Hr-MSTN cDNA was comprised of 2346 base pairs that encoded 489 amino acids and that contained structural characteristics typical of the transforming growth factor-β superfamily, including C-terminal signal peptide, propeptide domain, and transforming growth factor-β regions. Gene expression analysis revealed ubiquitous transcript expression in all tested red abalone tissues, but the muscle and mantle evidenced the highest transcriptional activity. RNA interference against MSTN mRNA significantly downregulated MSTN at 14 days post-injection, correlating with an upregulation of the insulin-related genes Insulin receptor, Growth factor receptor bound 2, and Proto-oncogene serine/threonine-protein kinase. These results suggest that MSTN silencing can promote activation of the insulin transcription pathway and consequently trigger somatic growth in the red abalone. This study is the first to evaluate the role of MSTN in gastropods using RNA interference, thus providing new perspectives for genetic improvement programs in abalone aquaculture.
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Characterization of the growth-related transcriptome in California red abalone (Haliotis Rufescens) through RNA-Seq analysis.
Marine Genomics, 2015Co-Authors: Diego Valenzuela-miranda, Miguel Ángel Del Río-portilla, Cristian Gallardo-escárateAbstract:One of the largest detriments in the abalone aquaculture industry is the inherently low growth rate of this marine gastropod. In order to confront this issue, greater molecular knowledge is needed on growth traits. Therefore, transcriptome analyses were performed using RNA-Seq for groups of California red abalones (Haliotis Rufescens) cultured under the same conditions, but with high growth rates (HGR) or low growth rates (LGR). De novo assembly generated 44312 contigs used as references for RNA-Seq analysis. Results showed a total of 1437 differentially expressed contigs, among which, 435 were up-regulated in the HGR group and 1002 in LGR individuals. Overall, LGR abalones evidenced a greater number of exclusive transcripts and differentially transcribed genes. These results provide a valuable resource of novel transcripts in this species and further understandings of the molecular bases regulating growth traits in H. Rufescens.
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Molecular cloning and expression of IRAK-4, IL-17 and I-κB genes in Haliotis Rufescens challenged with Vibrio anguillarum.
Fish & shellfish immunology, 2014Co-Authors: Valentina Valenzuela-muñoz, Cristian Gallardo-escárateAbstract:Abstract The candidate genes interleukin-1 receptor associated kinase 4 (IRAK-4), Interleukin 17 (IL-17) and Inhibitor of NF-κB (I-κB) were cloned and evaluated in Californian abalone (Haliotis Rufescens) hemocytes in response to Vibrio anguillarum. Molecular characterization evidenced that HrI-κB has a full cDNA sequence of 3027 bp with an encoding region of 401 amino acids (aa), HrIRAK-4 comprised 1969 bp that encoded for 516 aa, and Hr-IL17 had a full sequence of 806 bp encoding for 165 aa. qPCR analysis showed the higher constitutive expression level of Hr-IL17 in hemocytes; meanwhile Hr-IκB and Hr-IRAK4 gene expression levels were higher in gills and mantle. The assessment of gene expression in hemocytes after infection with V. anguillarum evidences the immune responses of Hr-IκB, Hr-IRAK4, and Hr-IL17 and their relationships through the NF-κB signaling pathway.
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Parentage assignment in hybrid abalones (Haliotis Rufescens × Haliotis discus hannai) based on microsatellite DNA markers
Aquaculture Research, 2013Co-Authors: Fabiola Lafargade La Cruz, Andrea Aguilar-espinoza, Cristian Gallardo-escárateAbstract:Parentage analysis in aquaculture determines genealogical relationships between broodstock and progeny when the parents are unknown. Thus, parentage analysis is a useful tool to establish pedigree reports in molecular-assisted selection programs. Here, we evaluated 10 heterologous microsatellite markers for parentage assignment in abalone hybrids produced from 43 abalone broodstocks of red abalone (Haliotis Rufescens) and Japanese abalone (H. discus hannai). The allele frequencies, exclusion probabilities and broodstock contributions were calculated using CERVUS, PAPA and GERUD software. The polymorphic information content (PIC) values showed that most of the microsatellite loci were highly informative (>0.7) and more than 90% of parentage assignment was possible with a minimum of 5–6 microsatellite markers. Parentage assignment for hybrid and pure-red progeny showed a better performance than pure-Japanese progeny. This result could be due to the high level of allele loss in the parental genotypes. In addition, results indicated that only two sires contributed over 80% and 90% of red and hybrid progenies, respectively. This study gives a new molecular tool to support marker-assisted selection in abalone hybrids produced in Chile.
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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Toxicokinetics and biotransformation of p-nitrophenol in red abalone (Haliotis Rufescens).
Aquatic toxicology (Amsterdam Netherlands), 2003Co-Authors: Patti L Tenbrook, Shellie M. Kendall, Mark R. Viant, Ronald S TjeerdemaAbstract:Abstract Red abalone ( Haliotis Rufescens ) were exposed to 3.6 μM (0.5 ppm) 14 C-labelled p -nitrophenol (PNP) for 24 h, then were allowed to depurate in clean seawater for another 24 h. Absorption, conditional uptake clearance and elimination rate constants were 0.12±0.04 h −1 , 3.2±1.1 ml g −1 h −1 and 0.05±0.02 h −1 , respectively. The sigmoidal shape of the PNP uptake curve suggests a biphasic process. A whole-organism total concentration factor (TCF) of 2.37±0.07 was determined from equilibrium tissue and water concentrations, with the highest concentration of PNP plus metabolites found in gill tissue (11.8±0.2 nmol g −1 , wet weight). Digestive gland, foot muscle and remaining body tissues accumulated 8.8±0.9, 7.7±0.6 and 7.5±0.6 nmol g −1 radiolabelled residues, respectively. Abalone depurated 91.6% of absorbed PNP within 24 h, of which 87.5±3.1% was unmetabolized parent compound, 13.1±3.1% was p -nitrophenylsulfate, 0.32±0.09% was p -nitroanisole, and 0.14±0.07% was p -acetamidophenol.
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sublethal effects of pentachlorophenol in abalone Haliotis Rufescens veliger larvae as measured by 31p nmr
Ecotoxicology and Environmental Safety, 2002Co-Authors: Scott L Shofer, Ronald S TjeerdemaAbstract:Toxicity tests with larval marine organisms are widely used as water quality-monitoring tools. Often employing a single morphological endpoint, they provide only limited insight into toxic action mechanisms. Since mechanistic observations can provide more sensitive endpoints of toxicity, the goal of this study was to modify existing in vivo31P-NMR techniques to evaluate the effects of pentachlorophenol (PCP) on high-energy phosphates in veliger larvae of the red abalone (Haliotis Rufescens), a species and life stage commonly used in developmental toxicity tests. Fluxes of phosphoarginine (PA), nucleoside triphosphates (NTPs), sugar phosphates (SPs), and inorganic phosphate (Pi), as well as in intracellular pH (pHi), were monitored via NMR using a flow-through exposure system. The exposure protocol included 1 h of clean seawater, 2 h of PCP (1.2 mg L−1) exposure, and 2 h of recovery in clean seawater. During PCP exposure, veligers displayed maximum declines in PA and NTP resonance intensities to 38±10% (P 0.05 for all values), while pHi increased to 7.08±0.11. When compared with adult abalone, veliger larvae responded similarly to PCP, differing mainly in their rapid recovery (2 h for larvae versus 6 h adults) and more severe acidification (a 0.08 pH unit decline versus a 0.03 pH unit decline). This report describes an application of NMR for small (≥200 μ) marine organisms using commonly available vertical-bore NMR magnets; it should prove adaptable for use with other similar larval forms.
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Interactions of chemical and natural stresses in the abalone (Haliotis Rufescens) as measured by surface-Probe localized 31P NMR
Marine Environmental Research, 1996Co-Authors: Ronald S Tjeerdema, Robert J. Kauten, Wanda S. Smith, Linda B Martello, Donald G. CrosbyAbstract:Abstract Application of nuclear magnetic resonance spectroscopy (NMR) for elucidating the sublethal actions of toxicants in intact aquatic organisms, and the influence of natural stress factors, has recently been demonstrated. Using a flow-through chamber, red abalones ( Haliotis Rufescens ) were exposed (at 14 °C) to ambient (35%.), hyposaline (25%.), or hyper saline (4 5 %.) seawater, with and without a sublethal concentration (1.2 mg l −1 ) of pentachlorophenol (PCP). They were then maintained in clean seawater (at the same salinity) to check both rate and degree of recovery; phosphagen changes in foot muscle were monitored by surface-probe localized 31 P NMR. Whereas different water salinities alone did not produce measurable effects, upon PCP exposure phosphoarginine levels declined, inorganic monophosphate levels increased, and intracellular pH decreased. Whereas during recovery all biochemical endpoints returned to normal, both onset and intensity of effects were significantly influenced in an unexpected manner by changes in seawater salinity. Application of 31 P NMR represents a powerful new tool for elucidating the influence of natural stress factors on pollutant actions in vivo , providing a more accurate assessment of environmental effects.
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Sublethal effects of hypoxia in the abalone (Haliotis Rufescens) as measured by in vivo31P NMR spectroscopy
Comparative Biochemistry and Physiology Part B: Comparative Biochemistry, 1991Co-Authors: Ronald S Tjeerdema, Robert J. Kauten, Donald G. CrosbyAbstract:Abstract 1. 1. Effects of hypoxia were investigated in red abalones (Haliotis Rufescens) using a flow-through exposure system and in vivo31P NMR spectroscopy. 2. 2. Following seawater acclimation, abalones were exposed to air for 1 hr, then seawater for 2.5 hr to check recovery; parallel controls were performed without air exposure. 3. 3. In foot muscle, hypoxia produced a decrease in phosphoarginine concentration and intracellular pH, an increase in inorganic monophosphate concentration, and no change in that of ATP; upon resubmergence, all effects generally recovered. 4. 4. The changes induced by hypoxia during normal tidal changes are consistent with the blockage of mitochondrial oxidative phosphorylation. 5. 5. Use of in vivo NMR allows measurement of the biochemical effects of natural stress factors in live, intact aquatic organisms in the laboratory.
R. S. Burton - One of the best experts on this subject based on the ideXlab platform.
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Genetic structure of natural populations of California red abalone (Haliotis Rufescens) using multiple genetic markers
Marine Biology, 2007Co-Authors: K. M. Gruenthal, L. K. Acheson, R. S. BurtonAbstract:Mitochondrial cytochrome oxidase subunit one (COI) sequence, nuclear microsatellites, and amplified fragment length polymorphisms (AFLPs) were used to evaluate connectivity among nine red abalone ( Haliotis Rufescens ) populations sampled between August 1998 and November 2003 along approximately 1,300 km of California coastline from Crescent City (41°46′N, 124°12′W) to San Miguel Island (34°02′N, 120°22′W). COI sequences and microsatellite genotypes did not show significant genetic divergence among nine sampled populations. A subset of five populations spanning the geographic range of the study was scored for 163 polymorphic AFLP markers. Of these, 41 loci showed significant divergence ( P
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genetic structure of natural populations of california red abalone Haliotis Rufescens using multiple genetic markers
Marine Biology, 2007Co-Authors: K. M. Gruenthal, L. K. Acheson, R. S. BurtonAbstract:Mitochondrial cytochrome oxidase subunit one (COI) sequence, nuclear microsatellites, and amplified fragment length polymorphisms (AFLPs) were used to evaluate connectivity among nine red abalone (Haliotis Rufescens) populations sampled between August 1998 and November 2003 along approximately 1,300 km of California coastline from Crescent City (41°46′N, 124°12′W) to San Miguel Island (34°02′N, 120°22′W). COI sequences and microsatellite genotypes did not show significant genetic divergence among nine sampled populations. A subset of five populations spanning the geographic range of the study was scored for 163 polymorphic AFLP markers. Of these, 41 loci showed significant divergence (P < 0.001) among populations. Still, no AFLP markers were diagnostic for any of the study populations, and assignment tests did not consistently assign individuals to the correct population. Although the AFLP data are the first to suggest there is significant genetic differentiation among California red abalone populations, the discordance between the different genetic markers needs further study before unambiguous conclusions can be drawn with respect to connectivity among the populations.
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Enhancement of red abalone Haliotis Rufescens stocks at San Miguel Island: reassessing a success story
Marine Ecology Progress Series, 2000Co-Authors: R. S. Burton, Mia J. TegnerAbstract:Outplanting of hatchery-reared juvenile abalone has received much attention as a strategy for enhancement of depleted natural stocks. Most outplants attempted to date appear to have been unsuccessful. However, based on genetic analyses of a population sample taken in 1992, it has recently been suggested that a 1979 outplanting of red abalone Haliotis Rufescens, on the south side of San Miguel Island (California, USA), was successful and probably sus- tained the fishery there through the 1980s. We resampled the San Miguel population in 1999 and found no genetic signa- ture of the outplants. Allelic frequencies in our 1999 sample closely resemble those observed in a pre-outplant 1979 south- ern California sample and two 1999 northern California pop- ulations. All genotypic frequencies were in Hardy-Weinberg expected proportions. We also assessed mtDNA diversity at San Miguel and found it not to differ from that of 2 robust northern California populations of H. Rufescens. Our results suggest that either the composition of the San Miguel abalone population changed rapidly between 1992 and 1999, or the genetic anomalies attributed to hatchery source for the 1992 sample were due to sample degradation or other laboratory artifacts. Since we lack samples from the 1992 collections, we cannot directly test which explanation is valid. However, sev- eral lines of reasoning call into question the earlier conclusion of outplant success.
Fernando Silva-aciares - One of the best experts on this subject based on the ideXlab platform.
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Transcriptomic and cellular response to bacterial challenge (pathogenic Vibrio parahaemolyticus) in farmed juvenile Haliotis Rufescens fed with or without probiotic diet.
Journal of Invertebrate Pathology, 2013Co-Authors: Fernando Silva-aciares, Dario Moraga, Michel Auffret, Arnaud Tanguy, Carlos RiquelmeAbstract:The abalone production in Chile has increased considerably in recent years with no sign of tapering off. Open and semi-closed circuits in the marine water zones in the north and south of Chile are the preferred areas of culture. Coastal ecosystems are subjected to a wide variety of contaminants that generate stress that affects populations via their impacts to individuals at both physiological and genetic levels. This work investigated the genomic and cellular response of post-weaning juvenile Haliotis Rufescens abalone under hatchery conditions, fed with probiotic diets, and subsequently challenged with Vibrio parahaemolyticus. The expression patterns of 16 selected genes associated with different metabolic pathways were analyzed using Real-Time PCR. Gene expression was then compared to immunological response parameters in the abalone and quantification of V. parahaemolyticus during the experimental period. Both transcriptomic and immunological analyses indicated significant alteration of physiological processes in H. Rufescens correlated to exposure to the pathogenic bacteria, as well as to probiotic nutrition.
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Effect of copper on the immunomodulatory activities of haemocytes in juveniles of the abalone Haliotis Rufescens cultivated under hatchery conditions
Aquaculture, 2013Co-Authors: Fernando Silva-aciares, Dario Moraga, Carlos RiquelmeAbstract:International audienceThe effect of short-term exposure to copper on the cellular and physiological response in haemocytes of juvenile abalone Haliotis Rufescens cultivated in hatcheries in the north of Chile is evaluated. The animals were exposed for 168 hours to concentrations of 2.5 μg/L and 10 μg/L of Cu+ 2, which have been reported as representative of coastal zones close to mining activity, particularly copper mining. The haemocytes were collected from the animals and the effect of the metal was quantified through the total haemocyte count (THC), phagocytosis, phenoloxidase activity, and generation of superoxide anions. The results showed that copper exposure decreased THC and phagocytosis significantly, while phenoloxidase activity and superoxide anions production increased significantly with respect to untreated controls. This study suggests a relation between exposure to the trace copper concentrations and the alterations of in vitro cellular and physiological parameters of the abalone's immune system in a dose- and time-dependent manner. This study emphasize the importance of heavy metal contamination on abalone cultures considering that the haemocytes are crucial for the proper function of the immune system and important health indicators to evaluate the effect of ambient stress factors on these organisms
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Identification of genes expressed in juvenile Haliotis Rufescens in response to different copper concentrations in the north of Chile under controlled conditions
Marine Pollution Bulletin, 2011Co-Authors: Fernando Silva-aciares, Manuel Zapata, Jennifer Tournois, Dario Moraga, Carlos RiquelmeAbstract:This study reports molecular markers potentially associated with resistance or sensitivity to the impact of copper in juvenile red abalone, Haliotis Rufescens, in the north of Chile under experimental conditions. Genomic analysis was made applying subtractive hybridization libraries (SSH) to identify genes up-and down regulated during cooper exposure in abalone over periods of 12 and 168 h exposed to 2.5 and 10 μg/L of Cu+2. Results obtained from the SSH library revealed 368 different sequences regulated by copper, that correspond to eight major physiological functions. The validation of these sequences obtained by SSH as well as their expression kinetics were made by PCR in real time on 14 potential genes regulated by metal stress. This study provides information for the characterization of potential genomic markers that may be used in future environmental monitoring and to investigate new mechanisms of stress to copper in this commercially important marine species.
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Use of macroalgae supplemented with probiotics in the Haliotis Rufescens (Swainson, 1822) culture in Northern Chile
Aquaculture Research, 2010Co-Authors: Fernando Silva-aciares, Paolo O Carvajal, Cristian Mejias, Carlos RiquelmeAbstract:In this study, we evaluate the use of macroalgae as vectors of probiotics bacteria into the digestive tract of abalone to improve their survival and growth. It is shown that when abalone Haliotis Rufescens of different sizes were fed with a natural diet composed of fronds of the macroalga Macrocystis integrifolia supplemented with a mixture of Vibrio sp. C21-UMA, Agarivorans albus F1-UMA and Vibrio sp. F15-UMA bacteria, there was a significant increase (P
