Base de dados : MEDLINE
Pesquisa : B01.050.500.644.080.500 [Categoria DeCS]
Referências encontradas : 67 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 7 ir para página                  

  1 / 67 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28278288
[Au] Autor:Tettelbach ST; Europe JR; Tettelbach CR; Havelin J; Rodgers BS; Furman BT; Velasquez M
[Ad] Endereço:Department of Biology, LIU-Post, Brookville, New York, United States of America.
[Ti] Título:Hard clam walking: Active horizontal locomotion of adult Mercenaria mercenaria at the sediment surface and behavioral suppression after extensive sampling.
[So] Source:PLoS One;12(3):e0173626, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Locomotion of infaunal bivalve mollusks primarily consists of vertical movements related to burrowing; horizontal movements have only been reported for a few species. Here, we characterize hard clam walking: active horizontal locomotion of adults (up to 118 mm shell length, SL) of the commercially important species, Mercenaria mercenaria, at the sediment surface-a behavior only briefly noted in the literature. We opportunistically observed walking over a 10-yr period, at 9 different sites in the Peconic Bays, New York, USA, and tested several hypotheses for the underlying cause of this behavior through quantitative field sampling and reproductive analyses. Hard clam walking was exhibited by males and females at equal frequency, predominantly during June/July and October, when clams were in peak spawning condition. Extensive walking behavior appears to be cued by a minimum population density; we suggest it may be mediated by unidentified pheromone(s), infaunal pressure waves and/or other unidentified factors. There was no directionality exhibited by walking clams, but individuals in an area of extensive walking were highly aggregated and walking clams were significantly more likely to move toward a member of the opposite sex. Thus, we conclude that hard clam walking serves to aggregate mature individuals prior to spawning, thereby facilitating greater fertilization success. In the process of investigating this behavior, however, we apparently oversampled one population and reduced clam densities below the estimated minimum threshold density and, in so doing, suppressed extensive walking for a period of >3 years running. This not only reinforces the importance of detailed field investigations of species biology and ecology, even for those that are considered to be well studied, but also highlights the need for greater awareness of the potential for research activities to affect focal species behavior.
[Mh] Termos MeSH primário: Comportamento Animal/fisiologia
Fertilização/fisiologia
Locomoção/fisiologia
Mercenaria/fisiologia
Atrativos Sexuais
Caminhada/fisiologia
[Mh] Termos MeSH secundário: Animais
Feminino
Masculino
Tamanho da Amostra
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Sex Attractants)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170906
[Lr] Data última revisão:
170906
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170310
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0173626


  2 / 67 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28171698
[Au] Autor:Rubin E; Tanguy A; Pales Espinosa E; Allam B
[Ad] Endereço:School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, 11794-5000, New York, USA.
[Ti] Título:Differential Gene Expression in Five Isolates of the Clam Pathogen, Quahog Parasite Unknown (QPX).
[So] Source:J Eukaryot Microbiol;64(5):647-654, 2017 Sep.
[Is] ISSN:1550-7408
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Quahog parasite unknown (QPX) is a thraustochytrid protist that infects the hard clam, Mercenaria mercenaria, causing significant economic losses along the northeastern coast of North America. Previous investigations noted differences in growth dynamics and virulence in QPX cells from different geographic locations. In order to probe the molecular determinants for these variations, we investigated the transcriptomic profiles of five geographically distinct QPX isolates using custom 15k 60-mer oligonucleotide arrays. A total of 1,263 transcripts were differentially expressed (DE) among the five QPX isolates. The hierarchical clustering of gene expression profiles showed that the QPX isolates from Raritan Bay (RB, NY) and from Provincetown Harbor (MA) were more similar to each other and diverged from QPX isolates from Peconic Bay (PB, NY) and Old Plantation Creek (VA), which had more similar gene expression profiles. The most prominent difference was based on 78 transcripts coding for heat shock proteins DE between the five QPX isolates. The study generated contrasting transcriptomic profiles for QPX isolated from northern (MA) and deeper (RB, NY) locations as compared to southern (VA) and shallower (PB, NY) areas, suggesting the adaptation of the parasite to local environmental, in particular temperature, conditions.
[Mh] Termos MeSH primário: Perfilação da Expressão Gênica/métodos
Proteínas de Protozoários/genética
Estramenópilas/isolamento & purificação
[Mh] Termos MeSH secundário: Adaptação Fisiológica
Animais
Análise por Conglomerados
Evolução Molecular
Regulação da Expressão Gênica
Mercenaria/parasitologia
Análise de Sequência com Séries de Oligonucleotídeos/métodos
Estramenópilas/classificação
Estramenópilas/genética
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Protozoan Proteins)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170919
[Lr] Data última revisão:
170919
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170208
[St] Status:MEDLINE
[do] DOI:10.1111/jeu.12400


  3 / 67 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28065550
[Au] Autor:Reitsma J; Murphy DC; Archer AF; York RH
[Ad] Endereço:Cape Cod Cooperative Extension & Woods Hole Sea Grant, PO Box 367, Barnstable, MA 02630, United States. Electronic address: jreitsma@barnstablecounty.org.
[Ti] Título:Nitrogen extraction potential of wild and cultured bivalves harvested from nearshore waters of Cape Cod, USA.
[So] Source:Mar Pollut Bull;116(1-2):175-181, 2017 Mar 15.
[Is] ISSN:1879-3363
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:As nitrogen entering coastal waters continues to be an issue, much attention has been generated to identify potential options that may help alleviate this stressor to estuaries, including the propagation of bivalves to remove excess nitrogen. Oysters (Crassostrea virginica) and quahogs (Mercenaria mercenaria) from numerous Cape Cod, MA, (USA) sources were analyzed for nitrogen content stored in tissues that would represent a net removal of nitrogen from a water body if harvested. Results showed local oysters average 0.69% nitrogen by total dry weight (mean 0.28gN/animal) and quahogs average 0.67% nitrogen by total dry weight (mean 0.22gN/animal); however, these values did vary by season and to a lesser extent by location or grow-out method. The differences in nitrogen content were largely related to the mass of shell or soft tissue. Nitrogen isotope data indicate shellfish from certain water bodies in the region are incorporating significant amounts of nitrogen from anthropogenic sources.
[Mh] Termos MeSH primário: Crassostrea/metabolismo
Mercenaria/metabolismo
Nitrogênio/metabolismo
[Mh] Termos MeSH secundário: Animais
Monitoramento Ambiental
Estuários
Massachusetts
Água do Mar
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
N762921K75 (Nitrogen)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170522
[Lr] Data última revisão:
170522
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170110
[St] Status:MEDLINE


  4 / 67 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:27901501
[Au] Autor:Rubin E; Werneburg GT; Pales Espinosa E; Thanassi DG; Allam B
[Ad] Endereço:School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000, USA.
[Ti] Título:Identification and characterization of peptidases secreted by quahog parasite unknown (QPX), the protistan parasite of hard clams.
[So] Source:Dis Aquat Organ;122(1):21-33, 2016 11 22.
[Is] ISSN:0177-5103
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Quahog parasite unknown (QPX) is a protistan parasite capable of causing deadly infections in the hard clam Mercenaria mercenaria, one of the most valuable shellfish species in the USA. QPX is an extracellular parasite found mostly in the connective tissue of clam mantle and, in more severe cases of infection, other clam organs. Histopathologic examinations revealed that QPX cells within clam tissues are typically surrounded by hollow areas that have been hypothesized to be, at least in part, a result of extracellular digestion of clam proteins by the parasite. We investigated peptidase activity in QPX extracellular secretions using sodium dodecyl sulfate-polyacrylamide gels containing gelatin as a co-polymerized substrate. Multiple peptidase activity bands of molecular weights ranging from 20 to 100 kDa were detected in QPX secretions derived from a variety of culture media. One major band of approximately 35 kDa was composed of subtilisin-like peptidases that were released by QPX cells in all studied media, suggesting that these are the most common peptidases used by QPX for nutrient acquisition. PCR quantification of mRNA encoding QPX subtilisins revealed that their expression changes with the protein substrate used in the culture media. A fast protein liquid chromatography (FPLC) was used to fractionate QPX extracellular secretions. An FPLC-fraction containing a subtilisin-type serine peptidase was able to digest clam plasma proteins, suggesting that this peptidase might be involved in the disease process, and making it a good candidate for further investigation as a possible virulence factor of the parasite.
[Mh] Termos MeSH primário: Mercenaria/parasitologia
Peptídeo Hidrolases/metabolismo
Estramenópilas/fisiologia
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Animais
Regulação Enzimológica da Expressão Gênica
Interações Hospedeiro-Parasita
Estramenópilas/enzimologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
EC 3.4.- (Peptide Hydrolases)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170622
[Lr] Data última revisão:
170622
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161201
[St] Status:MEDLINE


  5 / 67 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:27655555
[Au] Autor:Ivanina AV; Sokolova IM
[Ad] Endereço:Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28269, USA.
[Ti] Título:Effects of intermittent hypoxia on oxidative stress and protein degradation in molluscan mitochondria.
[So] Source:J Exp Biol;219(Pt 23):3794-3802, 2016 Dec 01.
[Is] ISSN:1477-9145
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Oxygen fluctuations represent a common stressor in estuarine and intertidal environments and can compromise the mitochondrial integrity and function in marine organisms. We assessed the role of mitochondrial protection mechanisms (ATP-dependent and -independent mitochondrial proteases, and antioxidants) in tolerance to intermittent hypoxia or anoxia in three species of marine bivalves: hypoxia-tolerant hard clams (Mercenaria mercenaria) and oysters (Crassostrea virginica), and a hypoxia-sensitive subtidal scallop (Argopecten irradians). In clams and oysters, mitochondrial tolerance to hypoxia (18 h at 5% O ), anoxia (18 h at 0.1% O ) and subsequent reoxygenation was associated with the ability to maintain the steady-state activity of ATP-dependent and -independent mitochondrial proteases and an anticipatory upregulation of the total antioxidant capacity under the low oxygen conditions. No accumulation of end-products of lipid or protein peroxidation was found during intermittent hypoxia or anoxia in clams and oysters (except for an increase in protein carbonyl concentration after hypoxia-reoxygenation in oysters). In contrast, hypoxia/anoxia and reoxygenation strongly suppressed activity of the ATP-dependent mitochondrial proteases in hypoxia-sensitive scallops. This suppression was associated with accumulation of oxidatively damaged mitochondrial proteins (including carbonylated proteins and proteins conjugated with a lipid peroxidation product malondialdehyde) despite high total antioxidant capacity levels in scallop mitochondria. These findings highlight a key role of mitochondrial proteases in protection against hypoxia-reoxygenation stress and adaptations to frequent oxygen fluctuations in intertidal mollusks.
[Mh] Termos MeSH primário: Hipóxia Celular/fisiologia
Crassostrea/metabolismo
Mercenaria/metabolismo
Mitocôndrias/metabolismo
Estresse Oxidativo/fisiologia
Pectinidae/metabolismo
Proteólise
[Mh] Termos MeSH secundário: Animais
Antioxidantes/metabolismo
Proteínas Mitocondriais/metabolismo
Oxigênio/metabolismo
Peptídeo Hidrolases/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antioxidants); 0 (Mitochondrial Proteins); EC 3.4.- (Peptide Hydrolases); S88TT14065 (Oxygen)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170803
[Lr] Data última revisão:
170803
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160923
[St] Status:MEDLINE


  6 / 67 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27269885
[Au] Autor:Wang K; Pales Espinosa E; Allam B
[Ad] Endereço:School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA.
[Ti] Título:Effect of "heat shock" treatments on QPX disease and stress response in the hard clam, Mercenaria mercenaria.
[So] Source:J Invertebr Pathol;138:39-49, 2016 Jul.
[Is] ISSN:1096-0805
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The hard clam, Mercenaria mercenaria, is one of the most valuable commercial mollusk species along the eastern coast of the United States. Throughout the past 2 decades, the hard clam industry in the Northeast was significantly impacted by disease outbreaks caused by a lethal protistan parasite known as Quahog Parasite Unknown (QPX). QPX is an opportunistic pathogen and the infection has been shown to be a cold water disease, where warmer conditions (above 21°C) lead to disease reduction and clam healing. In vitro studies also showed a sharp reduction in parasite growth and survivorship at temperatures exceeding 27°C. In this study, we evaluated the effect of short-term exposures to high temperatures on QPX disease dynamic and clam recovery. Infected clams were collected from an enzootic site and subsequently submitted to one of ten "heat shock" treatments involving a gradient of temperatures and exposure times. QPX prevalence was compared before and 10weeks after heat shock to assess the effect of each treatment on disease progress. Expression of several stress-related genes was measured 1 and 7days after heat shock using qPCR to evaluate the effect of each treatment on clam physiology. Anti-QPX activity in clam plasma was also measured in an attempt to link changes in defense factors to thermal stress and disease progress. Our results suggest that brief exposures to moderate high temperatures promote the greatest remission while imposing the mildest stress to clams. These results are discussed with the aim of providing the industry with possible strategies to mitigate QPX disease.
[Mh] Termos MeSH primário: Hipertermia Induzida/métodos
Mercenaria/parasitologia
Infecções Protozoárias em Animais/terapia
[Mh] Termos MeSH secundário: Animais
Distribuição Aleatória
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170915
[Lr] Data última revisão:
170915
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160609
[St] Status:MEDLINE


  7 / 67 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27252455
[Au] Autor:Ivanina AV; Nesmelova I; Leamy L; Sokolov EP; Sokolova IM
[Ad] Endereço:Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223, USA.
[Ti] Título:Intermittent hypoxia leads to functional reorganization of mitochondria and affects cellular bioenergetics in marine molluscs.
[So] Source:J Exp Biol;219(Pt 11):1659-74, 2016 Jun 01.
[Is] ISSN:1477-9145
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Fluctuations in oxygen (O2) concentrations represent a major challenge to aerobic organisms and can be extremely damaging to their mitochondria. Marine intertidal molluscs are well-adapted to frequent O2 fluctuations, yet it remains unknown how their mitochondrial functions are regulated to sustain energy metabolism and prevent cellular damage during hypoxia and reoxygenation (H/R). We used metabolic control analysis to investigate the mechanisms of mitochondrial responses to H/R stress (18 h at <0.1% O2 followed by 1 h of reoxygenation) using hypoxia-tolerant intertidal clams Mercenaria mercenaria and hypoxia-sensitive subtidal scallops Argopecten irradians as models. We also assessed H/R-induced changes in cellular energy balance, oxidative damage and unfolded protein response to determine the potential links between mitochondrial dysfunction and cellular injury. Mitochondrial responses to H/R in scallops strongly resembled those in other hypoxia-sensitive organisms. Exposure to hypoxia followed by reoxygenation led to a strong decrease in the substrate oxidation (SOX) and phosphorylation (PHOS) capacities as well as partial depolarization of mitochondria of scallops. Elevated mRNA expression of a reactive oxygen species-sensitive enzyme aconitase and Lon protease (responsible for degradation of oxidized mitochondrial proteins) during H/R stress was consistent with elevated levels of oxidative stress in mitochondria of scallops. In hypoxia-tolerant clams, mitochondrial SOX capacity was enhanced during hypoxia and continued rising during the first hour of reoxygenation. In both species, the mitochondrial PHOS capacity was suppressed during hypoxia, likely to prevent ATP wastage by the reverse action of FO,F1-ATPase. The PHOS capacity recovered after 1 h of reoxygenation in clams but not in scallops. Compared with scallops, clams showed a greater suppression of energy-consuming processes (such as protein turnover and ion transport) during hypoxia, indicated by inactivation of the translation initiation factor EIF-2α, suppression of 26S proteasome activity and a dramatic decrease in the activity of Na(+)/K(+)-ATPase. The steady-state levels of adenylates were preserved during H/R exposure and AMP-dependent protein kinase was not activated in either species, indicating that the H/R exposure did not lead to severe energy deficiency. Taken together, our findings suggest that mitochondrial reorganizations sustaining high oxidative phosphorylation flux during recovery, combined with the ability to suppress ATP-demanding cellular functions during hypoxia, may contribute to high resilience of clams to H/R stress and help maintain energy homeostasis during frequent H/R cycles in the intertidal zone.
[Mh] Termos MeSH primário: Organismos Aquáticos/fisiologia
Metabolismo Energético
Hipóxia/fisiopatologia
Mercenaria/fisiologia
Mitocôndrias/metabolismo
Pectinidae/fisiologia
[Mh] Termos MeSH secundário: Aconitato Hidratase/genética
Aconitato Hidratase/metabolismo
Difosfato de Adenosina/farmacologia
Aerobiose/efeitos dos fármacos
Anaerobiose/efeitos dos fármacos
Animais
Organismos Aquáticos/efeitos dos fármacos
Biomarcadores/metabolismo
Metabolismo Energético/efeitos dos fármacos
Hepatopâncreas/efeitos dos fármacos
Hepatopâncreas/fisiopatologia
Homeostase/efeitos dos fármacos
Cinética
Potencial da Membrana Mitocondrial/efeitos dos fármacos
Mercenaria/efeitos dos fármacos
Mitocôndrias/efeitos dos fármacos
Oxirredução/efeitos dos fármacos
Estresse Oxidativo/efeitos dos fármacos
Oxigênio/farmacologia
Pectinidae/efeitos dos fármacos
Fosforilação/efeitos dos fármacos
Protease La/genética
Protease La/metabolismo
Complexo de Endopeptidases do Proteassoma/metabolismo
Prótons
RNA Mensageiro/genética
RNA Mensageiro/metabolismo
Descanso/fisiologia
ATPase Trocadora de Sódio-Potássio/metabolismo
Estresse Fisiológico/efeitos dos fármacos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Biomarkers); 0 (Protons); 0 (RNA, Messenger); 61D2G4IYVH (Adenosine Diphosphate); EC 3.4.21.53 (Protease La); EC 3.4.25.1 (Proteasome Endopeptidase Complex); EC 3.6.3.9 (Sodium-Potassium-Exchanging ATPase); EC 4.2.1.3 (Aconitate Hydratase); S88TT14065 (Oxygen)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170811
[Lr] Data última revisão:
170811
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160603
[St] Status:MEDLINE
[do] DOI:10.1242/jeb.134700


  8 / 67 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27050966
[Au] Autor:Ning YF; Li ZB; Mao XQ; Li BB; Huang YS; Yuan Y; Shangguan JB
[Ad] Endereço:Fisheries College, Jimei University, Xiamen, China.
[Ti] Título:Isolation and characterization of novel microsatellite markers in Mercenaria mercenaria.
[So] Source:Genet Mol Res;15(1), 2016 Mar 18.
[Is] ISSN:1676-5680
[Cp] País de publicação:Brazil
[La] Idioma:eng
[Ab] Resumo:Mercenaria mercenaria, also known as the hard clam, is widely distributed in the coastal waters of temperate and tropical areas in the Asian Pacific region. This species is widely popular in the international market, especially in the United States, Europe, and other Western countries, because of its high protein value, taste, and simple farming requirements. In this study, 17 novel microsatellite loci from the M. mercenaria genome were developed using the fast isolation by amplified fragment length polymorphism of sequences containing repeats protocol. Thirty-two wild individuals were used to evaluate the degree of polymorphism of these markers. Results indicated that there were 11 polymorphic loci and six monomorphic loci, and the number of alleles per locus and the polymorphism information content ranged from two to six and from 0.059 to 0.498, respectively. The observed and expected heterozygosity varied from 0.0625 to 0.5333 and 0.0615 to 0.4977, respectively. The Y1-4 locus deviated significantly from Hardy-Weinberg equilibrium (HWE) after Bonferroni correction was applied, while the other loci were in HWE. These loci will provide useful information for M. mercenaria population genetic studies.
[Mh] Termos MeSH primário: Mercenaria/genética
Repetições de Microssatélites/genética
[Mh] Termos MeSH secundário: Alelos
Animais
Loci Gênicos/genética
Polimorfismo Genético/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Em] Mês de entrada:1701
[Cu] Atualização por classe:170112
[Lr] Data última revisão:
170112
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160407
[St] Status:MEDLINE
[do] DOI:10.4238/gmr.15017497


  9 / 67 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27044911
[Au] Autor:Haider F; Falfushynska H; Ivanina AV; Sokolova IM
[Ad] Endereço:Department of Biological Sciences, University of North Carolina at Charlotte, 9201 University City Blvd., Charlotte, NC 28223, United States.
[Ti] Título:Effects of pH and bicarbonate on mitochondrial functions of marine bivalves.
[So] Source:Comp Biochem Physiol A Mol Integr Physiol;198:41-50, 2016 Aug.
[Is] ISSN:1531-4332
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Estuarine organisms including mollusks are exposed to periodic oxygen deficiency (hypoxia) that leads to a decrease in intracellular pH and accumulation of bicarbonate (HCO3(-)). These changes can affect cellular bioenergetics; however, their effects on mitochondria of estuarine mollusks are not well understood. We determined the interactive effects of bicarbonate (0-10mM) and pH (7.2 and 6.5) on mitochondrial oxygen consumption (MO2), membrane potential (Δψ) and production of reactive oxygen species (ROS) in two common estuarine bivalves - hard clams Mercenaria mercenaria, and bay scallops Argopecten irradians. In both species, elevated HCO3(-) levels suppressed ADP-stimulated (state 3) MO2 but had little effect on the resting (state 4) respiration. These effects were not mediated by the soluble adenylyl cyclase or cyclic AMP. Effects of the low pH (6.5) on mitochondrial traits were species-specific and depended on the substrate oxidized by the mitochondria. Mild acidosis (pH6.5) had minimal effects on MO2 and Δψ of the bivalve mitochondria oxidizing pyruvate but led to increased rates of ROS production in clams (ROS production could not be measured in scallops). In succinate-respiring mitochondria of clams, mild acidosis suppressed MO2 and increased mitochondrial coupling, while in scallop mitochondria the effects of low pH were opposite. Suppression of mitochondrial oxidative phosphorylation by bicarbonate and/or acidosis may contribute to the metabolic rate depression during shell closure or environmental hypoxia/hypercapnia. These findings have implications for understanding the physiological mechanisms involved in regulation of mitochondrial bioenergetics during hypoxia exposure in estuarine bivalves.
[Mh] Termos MeSH primário: Bicarbonatos/farmacologia
Mercenaria/metabolismo
Mitocôndrias/metabolismo
Pectinidae/metabolismo
[Mh] Termos MeSH secundário: Adenilil Ciclases/metabolismo
Animais
AMP Cíclico/metabolismo
Estuários
Concentração de Íons de Hidrogênio
Potencial da Membrana Mitocondrial/efeitos dos fármacos
Mercenaria/efeitos dos fármacos
Mitocôndrias/efeitos dos fármacos
Pectinidae/efeitos dos fármacos
Espécies Reativas de Oxigênio/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bicarbonates); 0 (Reactive Oxygen Species); E0399OZS9N (Cyclic AMP); EC 4.6.1.1 (Adenylyl Cyclases)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170613
[Lr] Data última revisão:
170613
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160406
[St] Status:MEDLINE


  10 / 67 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
PubMed Central Texto completo
Texto completo
[PMID]:26921237
[Au] Autor:Wang K; del Castillo C; Corre E; Pales Espinosa E; Allam B
[Ad] Endereço:School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY, 11794-5000, USA. kailai.wang@stonybrook.edu.
[Ti] Título:Clam focal and systemic immune responses to QPX infection revealed by RNA-seq technology.
[So] Source:BMC Genomics;17:146, 2016 Feb 27.
[Is] ISSN:1471-2164
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: The hard clam Mercenaria mercenaria is an important seafood species widely exploited along the eastern coasts of the United States and play a crucial role in coastal ecology and economy. Severe hard clam mortalities have been associated with the protistan parasite QPX (Quahog Parasite Unknown). QPX infection establishes in pallial organs with the lesions typically characterized as nodules, which represent inflammatory masses formed by hemocyte infiltration and encapsulation of parasites. QPX infection is known to induce host changes on both the whole-organism level and at specific lesion areas, which imply systemic and focal defense responses, respectively. However, little is known about the molecular mechanisms underlying these alterations. RESULTS: RNA-seq was performed using Illumina Hiseq 2000 (641 Million 100 bp reads) to characterize M. mercenaria focal and systemic immune responses to QPX. Transcripts were assembled and the expression levels were compared between nodule and healthy tissues from infected clams, and between these and tissues from healthy clams. De novo assembly reconstructed a consensus transcriptome of 62,980 sequences that was functionally-annotated. A total of 3,131 transcripts were identified as differentially expressed in different tissues. Results allowed the identification of host immune factors implicated in the systemic and focal responses against QPX and unraveled the pathways involved in parasite neutralization. Among transcripts significantly modulated upon host-pathogen interactions, those involved in non-self recognition, signal transduction and defense response were over-represented. Alterations in pathways regulating hemocyte focal adhesion, migration and apoptosis were also demonstrated. CONCLUSIONS: Our study is the first attempt to thoroughly characterize M. mercenaria transcriptome and identify molecular features associated with QPX infection. It is also one of the first studies contrasting focal and systemic responses to infections in invertebrates using high-throughput sequencing. Results identified the molecular signatures of clam systemic and focal defense responses, to collectively mediate immune processes such as hemocyte recruitment and local inflammation. These investigations improve our understanding of bivalve immunity and provide molecular targets for probing the biological bases of clam resistance towards QPX.
[Mh] Termos MeSH primário: Interações Hospedeiro-Parasita
Mercenaria/imunologia
Análise de Sequência de RNA/métodos
Transcriptoma
[Mh] Termos MeSH secundário: Animais
Mercenaria/parasitologia
Parasitos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Em] Mês de entrada:1609
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160228
[St] Status:MEDLINE
[do] DOI:10.1186/s12864-016-2493-9



página 1 de 7 ir para página                  
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde