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1.
Environ Sci Pollut Res Int ; 27(1): 882-889, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31820245

RESUMO

The European flat oyster (Ostrea edulis L.) represents an economically important oyster production in Southern Italy, widespread in natural beds along the coast. The practice to be eaten raw is an everlasting concern for possible health risk with a need to stringently monitor the health of aquatic environment. A screening survey using histopathological examination was undertaken by harvesting O. edulis from different sites along the Apulian coast of Italy. Tissue samples of the digestive gland, kidney, gonad, and gill were provided for morphologic study in light microscopy (LM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) analysis. The LM observations revealed spherical cytoplasmic inclusions as basophilic prokaryote colonies in 13/250 oysters. The TEM and SEM confirmed the presence of intracytoplasmic inclusions of Rickettsia-like organisms (RLOs), merely in the epithelial cells of the digestive gland tubule tissues in the 13 oysters. Within intracytoplasmic vacuoles, RLOs exhibited a prokaryotic characteristic ultrastructure with transverse binary fission, a DNA zone full of chromatin fibers and a granular periplasmic ribosome zone. O. edulis were found positive for RLOs in wild oysters from Manfredonia, while the other sites were found free of pathological inclusions. Thus, we present the first report of a Rickettsia-like infection in the Apulian wild oyster (O. edulis) from Italy, including an ultrastructural description and pathological characterization.


Assuntos
Monitoramento Ambiental , Ostrea/microbiologia , Rickettsia , Animais , Células Epiteliais , Brânquias , Itália , Microscopia Eletrônica de Transmissão
2.
PLoS One ; 14(10): e0224249, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31648244

RESUMO

Natural history collections are fundamental for biodiversity research as well as for any applied environment-related research. These collections can be seen as archives of earth´s life providing the basis to address highly relevant scientific questions such as how biodiversity changes in certain environments, either through evolutionary processes in a geological timescale, or by man-made transformation of habitats throughout the last decades and/or centuries. A prominent example is the decline of the European flat oyster Ostrea edulis Linneaus, 1758 in the North Sea and the concomitant invasion of the common limpet slipper Crepidula fornicata, which has been implicated to have negative effects on O. edulis. We used collections to analyse population changes in both species in the North Sea. In order to reconstruct the change in distribution and diversity over the past 200 years, we combined the temporal and spatial information recorded with the collected specimens contained in several European natural history collections. Our data recover the decline of O. edulis in the North Sea from the 19th century to the present and the process of invasion of C. fornicata. Importantly, the decline of O. edulis was nearly completed before C. fornicata appeared in the North Sea, suggesting that the latter had nothing to do with the local extinction of O. edulis in the North Sea.


Assuntos
Distribuição Animal/fisiologia , Biodiversidade , Ecossistema , Espécies Introduzidas/história , Ostrea/fisiologia , Animais , História do Século XIX , História do Século XX , História do Século XXI , Mar do Norte
3.
Fish Shellfish Immunol ; 93: 958-964, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31442589

RESUMO

The protozoan parasite Bonamia ostreae has been associated with the decline of flat oyster Ostrea edulis populations in some European countries. Control of shellfish diseases mostly relies on prevention measures including transfer restrictions and stock management measures such as breeding programmes. These prevention and mitigation measures require a better understanding of interactions between host and pathogens. Previous in vitro studies allowed identifying apoptosis as a mechanism activated by the flat oyster in response to B. ostreae. However, these experiments also suggested that the parasite is able to regulate apoptosis in order to survive and multiply within hemocytes. By simplifying the conditions of infection, in vitro studies allow identifying most distinct features of the response of the host. In order to appreciate the relative importance of apoptosis in this response at the oyster scale, in vivo trials were carried out by injecting with parasites oysters from two French locations, Quiberon Bay (Brittany) and Diana Lagoon (Corsica). Apoptosis was investigated on pools of hemolymph from oysters collected at early and later times after injection using previously developed tools. Apoptotic cellular activities including intracytoplasmic calcium concentration, mitochondrial membrane potential and phosphatidyl serine externalization were analysed using flow cytometry. Moreover, the expression of flat oyster genes involved in both extrinsic and intrinsic pathways was measured using real time quantitative PCR.


Assuntos
Apoptose/imunologia , Haplosporídios/fisiologia , Interações Hospedeiro-Parasita/imunologia , Ostrea/imunologia , Animais , Citometria de Fluxo , França , Ostrea/parasitologia
4.
Dis Aquat Organ ; 132(3): 181-189, 2019 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-31188133

RESUMO

Apicomplexan-X (APX) is a significant pathogen of the flat oyster Ostrea chilensis in New Zealand. The life cycle and host range of this species are poorly known, with only the zoite stage identified. Here, we report the use of molecular approaches and histology to confirm the presence of APX in samples of green-lipped mussels Perna canaliculus, Mediterranean mussels Mytilus galloprovincialis and hairy mussels Modiolus areolatus collected from widely distributed locations in New Zealand. The prevalence of APX infection estimated by PCR was 22.2% (n = 99) and 50% (n = 30) in cultured green-lipped mussels from Nelson and Coromandel, respectively; 0.8% (n = 258), 3.3% (n = 150) and 35.3% (n = 17) in wild Mediterranean mussels from Nelson, Foveaux Strait and Golden Bay, respectively; and 46.7% (n = 30) in wild hairy mussels from Foveaux Strait. Histology detected all cases of PCR that were positive with APX and appeared to be more sensitive. The prevalence of APX estimated by histology in green-lipped mussels from Coromandel was 60% versus 50% by PCR, and 4.3%, 10.7% and 52.9% by histology versus 0.8%, 3.3% and 35.3% by PCR in wild Mediterranean mussels from Nelson, Foveaux Strait and Golden Bay, respectively. The specific identity of the parasite found in mussels was determined by sequencing PCR products for a portion (676 bp) of the 18S rRNA gene; the resulting sequences were 99-100% similar to APX found in flat oysters. Phylogenetic analyses also confirmed that all isolates from green-lipped, Mediterranean and hairy mussels grouped with APX isolates previously identified from flat oysters. This study indicates the wide geographical distribution of APX and highlights the potentially multi-host specific distribution of the parasite in commercially important bivalve shellfish.


Assuntos
Ostrea , Animais , Nova Zelândia , Filogenia , Reação em Cadeia da Polimerase
5.
Mar Environ Res ; 144: 240-245, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30739812

RESUMO

The neurotoxic complex saxitoxin, is a group of marine toxins that historically has significantly impacted human health and the ability to utilize marine resources. A steady increase in the distribution and intensity of Alexandrium catenella blooms in Chile, and around the world, has caused major ecological and socioeconomic impacts, putting this type of dinoflagellate, and its toxicity, in the spotlight. Ostrea chilensis is a commercially and ecologically important resource harvested from wild populations and farmed in centers of southern Chile, where it is exposed to large harmful algal blooms of the type that can cause paralysis in humans. This study contributes to our understanding about the transfer of toxins from A. catenella cells to juvenile and adult Ostrea chilensis by tracking transformations of the neurotoxic complex until it reaches its most stable molecular form in the intracellular environment of O. chilensis tissues. These biotransformations are different in O. chilensis juveniles and adults, indicating a differentiated response for these two life stages of this bivalve species. These studies can be used for similar analyses in other ecologically and commercially important species of filter feeding organisms, providing greater understanding of the specific interactions of bivalves in scenarios of toxic dinoflagellate proliferations (e.g. A. catenella blooms).


Assuntos
Biotransformação , Dinoflagelados , Proliferação Nociva de Algas , Ostrea/metabolismo , Saxitoxina/metabolismo , Animais , Chile
6.
Mar Pollut Bull ; 139: 141-149, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30686412

RESUMO

Ocean acidification (OA) is well-known for impairing marine calcification; however, the end response of several essential species to this perturbation remains unknown. Decreased pH and saturation levels (Ω) of minerals under OA is projected to alter shell crystallography and thus to reduce shell mechanical properties. This study examined this hypothesis using a commercially important estuarine oyster Magallana hongkongensis. Although shell damage occurred on the outmost prismatic layer and the undying myostracum at decreased pH 7.6 and 7.3, the major foliated layer was relatively unharmed. Oysters maintained their shell hardness and stiffness through altered crystal unit orientation under pH 7.6 conditions. However, under the undersaturated conditions (ΩCal ~ 0.8) at pH 7.3, the realigned crystal units in foliated layer ultimately resulted in less stiff shells which indicated although estuarine oysters are mechanically resistant to unfavorable calcification conditions, extremely low pH condition is still a threat to this essential species.


Assuntos
Exoesqueleto/química , Carbonato de Cálcio/química , Dióxido de Carbono/análise , Ostrea/química , Água do Mar/química , Exoesqueleto/ultraestrutura , Animais , Fenômenos Biomecânicos , Calcificação Fisiológica , Cristalografia , Concentração de Íons de Hidrogênio , Microscopia Eletroquímica de Varredura , Ostrea/crescimento & desenvolvimento , Ostrea/ultraestrutura
7.
Mar Pollut Bull ; 138: 312-321, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30660279

RESUMO

The European oyster Ostrea edulis is a keystone species that is internationally recognised as 'threatened and declining' in the NE Atlantic by OSPAR and several nations have consequently adopted strategies for its conservation and restoration. Understanding the settlement behaviour of O. edulis larvae is crucial to inform these strategies. We compared the efficiency of several treatments in triggering settlement. The most effective settlement occurred with the presence of conspecifics: 100% settled in <23 h. Marine stones with habitat-associated biofilms induced 81% settlement that started after a 45 h delay. Sterile shells and terrestrial stones did not induce more settlement than control treatments. These results indicate that O. edulis larvae are gregarious and finely-tuned to settle in response to cues which are indicative of their adult habitat requirements. The role of chemical cues in mediating settlement, and the importance of this to restoration, are discussed.


Assuntos
Comportamento Animal , Conservação dos Recursos Naturais , Recuperação e Remediação Ambiental , Ostrea/fisiologia , Animais , Monitoramento Ambiental , Larva , Ostrea/crescimento & desenvolvimento
8.
Mar Environ Res ; 143: 82-92, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30471787

RESUMO

Ocean acidification and warming may threaten future seafood production, safety and quality by negatively impacting the fitness of marine species. Identifying changes in nutritional quality, as well as species most at risk, is crucial if societies are to secure food production. Here, changes in the biochemical composition and nutritional properties of the commercially valuable oysters, Magallana gigas and Ostrea edulis, were evaluated following a 12-week exposure to six ocean acidification and warming scenarios that were designed to reflect the temperature (+3 °C above ambient) and atmospheric pCO2 conditions (increase of 350-600 ppm) predicted for the mid-to end-of-century. Results suggest that O. edulis, and especially M. gigas, are likely to become less nutritious (i.e. containing lower levels of protein, lipid, and carbohydrate), and have reduced caloric content under ocean acidification and warming. Important changes to essential mineral composition under ocean acidification and warming were evident in both species; enhanced accumulation of copper in M. gigas may be of concern regarding consumption safety. In light of these findings, the aquaculture industry may wish to consider a shift in focus toward species that are most robust to climate change and less prone to deterioration in quality, in order to secure future food provision and socio-economic benefits of aquaculture.


Assuntos
Ostrea/metabolismo , Ostreidae/metabolismo , Frutos do Mar , Animais , Aquicultura , Dióxido de Carbono , Qualidade dos Alimentos , Aquecimento Global , Concentração de Íons de Hidrogênio , Ostrea/química , Ostreidae/química , Água do Mar/química
9.
Mar Environ Res ; 143: 124-140, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30482397

RESUMO

Shifting environmental conditions are known to be important triggers of oyster diseases. The mechanism(s) behind these synergistic effects (interplay between host, environment and pathogen/s) are often not clear, although there is evidence that shifts in environmental conditions can affect oyster immunity, and pathogen growth and virulence. However, the impact of shifting environmental parameters on the oyster microbiome and how this affects oyster health and susceptibility to infectious pathogens remains understudied. In this review, we summarise the major diseases afflicting oysters with a focus on the role of environmental factors that can catalyse or amplify disease outbreaks. We also consider the potential role of the oyster microbiome in buffering or augmenting oyster disease outbreaks and suggest that a deeper understanding of the oyster microbiome, its links to the environment and its effect on oyster health and disease susceptibility, is required to develop new frameworks for the prevention and management of oyster diseases.


Assuntos
Crassostrea , Interações Hospedeiro-Patógeno/imunologia , Microbiota , Ostrea , Animais , Aquicultura , Mudança Climática , Crassostrea/imunologia , Crassostrea/microbiologia , Crassostrea/parasitologia , Crassostrea/virologia , Surtos de Doenças , Imunidade Celular , Biologia Marinha , Ostrea/imunologia , Ostrea/microbiologia , Ostrea/parasitologia , Ostrea/virologia , Frutos do Mar
10.
J Fish Dis ; 42(1): 63-74, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30324720

RESUMO

Bonamia spp. parasites threaten flat oyster (Ostrea spp.) farming worldwide. Understanding test performance is important for designing surveillance and interpreting diagnostic results. Following a pilot survey which found low Bonamia sp. intensity in farmed Ostrea angasi, we tested further oysters (n = 100-150) from each of three farms for Bonamia sp. using heart smear, histology and qPCR. We used a Bayesian Latent Class Model to assess diagnostic sensitivity (DSe) and specificity (DSp) of these tests individually or in combination, and to assess prevalence. Histology was the best individual test (DSe 0.76, DSp 0.93) compared to quantitative polymerase chain reaction (qPCR) (DSe 0.69, DSp 0.93) and heart smear (DSe 0.61, DSp 0.60). Histology combined with qPCR and defining a positive from either test as an infected case maximized test performance (DSe 0.91, DSp 0.88). Prevalence was higher at two farms in a high-density oyster growing region than at a farm cultivating oysters at lower density. Parasite intensities were lower than in New Zealand and European studies, and this is probably contributed to differences in the performance of test when compared to other studies. Understanding diagnostic test performance in different populations can support the development of improved Bonamia surveillance programs.


Assuntos
Doenças dos Peixes/diagnóstico , Doenças dos Peixes/parasitologia , Haplosporídios , Ostrea/parasitologia , Infecções Protozoárias em Animais/diagnóstico , Animais , Aquicultura , Doenças dos Peixes/epidemiologia , Coração/parasitologia , Técnicas Histológicas/veterinária , Prevalência , Infecções Protozoárias em Animais/epidemiologia , Reação em Cadeia da Polimerase em Tempo Real , Austrália do Sul/epidemiologia
11.
Food Funct ; 9(12): 6577-6585, 2018 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-30488053

RESUMO

Oyster, which is rich in protein and widely used as a marine traditional Chinese medicine, was believed to have good curative effects in health care and on chronic diseases. This study was designed to evaluate the anti-fatigue and anti-oxidant effects of oyster hydrolysate. Oyster meat (OM) was hydrolyzed with a complex protease, and oyster hydrolysate (OH) was separated by a 6 kDa ultrafiltration membrane into two fractions, OH-I (<6 kDa) and OH-II (≥6 kDa). The anti-fatigue effects of OM, OH, OH-I and OH-II groups were first investigated, and then the antioxidant activities of OH-I and OH-II were further analyzed. Anti-fatigue experimental results showed that OH-I displayed the strongest activity among the four groups. Compared to the control group, OH-I significantly prolonged swimming time (67.79%), increased the content of muscle glycogen (45.65%) and liver glycogen (49.01%), and reduced the content of blood urea nitrogen (BUN) (18.44%) (P < 0.05). Meanwhile, OH-I showed excellent chemical and cellular antioxidant activities, especially when the concentration increased; its antioxidant activity was significantly better than that of OH-II (P < 0.05). Results of an amino acid analysis showed that OH-I was rich in branched-chain amino acids (10.84 g per 100 g), Glu (8.63 g per 100 g), Tau (1.68 g per 100 g), Asp (5.02 g per 100 g) and Arg (3.61 g per 100 g), which were expected to contribute to its antioxidant and anti-fatigue activities.


Assuntos
Antioxidantes/metabolismo , Fadiga/dietoterapia , Ostrea/química , Peptídeo Hidrolases/química , Animais , Antioxidantes/química , Biocatálise , Fadiga/metabolismo , Glicogênio/metabolismo , Humanos , Glicogênio Hepático/metabolismo , Masculino , Carne/análise , Camundongos , Músculos/metabolismo , Ostrea/metabolismo , Hidrolisados de Proteína/química , Hidrolisados de Proteína/metabolismo
12.
Mar Environ Res ; 142: 178-189, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30352700

RESUMO

Globally, non-native species (NNS) have been introduced and now often entirely replace native species in captive aquaculture; in part, a result of a perceived greater resilience of NSS to climate change and disease. Here, the effects of ocean acidification and warming on metabolic rate, feeding rate, and somatic growth was assessed using two co-occurring species of oysters - the introduced Pacific oyster Magallana gigas (formerly Crassostrea gigas), and native flat oyster Ostrea edulis. Biological responses to increased temperature and pCO2 combinations were tested, the effects differing between species. Metabolic rates and energetic demands of both species were increased by warming but not by elevated pCO2. While acidification and warming did not affect the clearance rate of O. edulis, M. gigas displayed a 40% decrease at 750 ppm pCO2. Similarly, the condition index of O. edulis was unaffected, but that of M. gigas was negatively impacted by warming, likely due to increased energetic demands that were not compensated for by increased feeding. These findings suggest differing stress from anthropogenic CO2 emissions between species and contrary to expectations, this was higher in introduced M. gigas than in the native O. edulis. If these laboratory findings hold true for populations in the wild, then continued CO2 emissions can be expected to adversely affect the functioning and structure of M. gigas populations with significant ecological and economic repercussions, especially for aquaculture. Our findings strengthen arguments in favour of investment in O. edulis restoration in UK waters.


Assuntos
Crassostrea/fisiologia , Temperatura Alta , Ostrea/fisiologia , Animais , Aquicultura , Metabolismo Energético , Aquecimento Global , Concentração de Íons de Hidrogênio
13.
Mol Ecol ; 27(21): 4225-4240, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30193406

RESUMO

The Olympia oyster (Ostrea lurida) is a foundation species inhabiting estuaries along the North American west coast. In California estuaries, O. lurida is adapted to local salinity regimes and populations differ in low salinity tolerance. In this study, oysters from three California populations were reared for two generations in a laboratory common garden and subsequently exposed to low salinity seawater. Comparative transcriptomics was then used to understand species-level responses to hyposmotic stress and population-level mechanisms underlying divergent salinity tolerances. Gene expression patterns indicate Olympia oysters are sensitive to hyposmotic stress: All populations respond to low salinity by up-regulating transcripts indicative of protein unfolding, DNA damage and cell cycle arrest after sub-lethal exposure. Among O. lurida populations, transcriptomic profiles differed constitutively and in response to low salinity. Despite two generations in common-garden conditions, transcripts encoding apoptosis modulators were constitutively expressed at significantly different levels in the most tolerant population. Expression of cell death regulators may facilitate cell fate decisions when salinity declines. Following low salinity exposure, oysters from the more tolerant population expressed a small number of mRNAs at significantly higher levels than less tolerant populations. Proteins encoded by these transcripts regulate ciliary activity within the mantle cavity and may function to prolong valve closure and reduce mortality in low salinity seawater. Collectively, gene expression patterns suggest sub-lethal impacts of hyposmotic stress in Olympia oysters are considerable and that even oysters with greater low salinity tolerance may be vulnerable to future freshwater flooding events.


Assuntos
Genética Populacional , Ostrea/genética , Tolerância ao Sal/genética , Transcriptoma , Adaptação Fisiológica/genética , Animais , California , Estuários , Salinidade
14.
Dis Aquat Organ ; 129(3): 199-205, 2018 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-30154280

RESUMO

Described here is a polymerase chain reaction (PCR) test to detect the apicomplexan-X (APX) parasite of a flat oyster species, Ostrea chilensis, endemic to New Zealand. The test primers target sequences in the in situ hybridisation probes identified to bind specifically to APX 18S rRNA and amplify a 723 bp DNA product. The test did not amplify 18S rRNA gene sequences of other apicomplexan species, including Toxoplasma gondii, Neospora caninum, Selenidium spp., Cephaloidophorida spp., Lecudina spp. and Thiriotia sp. Of 73 flat oysters identified by histology to be infected with APX at different severities, 69 (95%) tested PCR-positive. Failure to amplify an internal control indicated the presence of PCR inhibitors in the 4 PCR-negative samples. The high analytical sensitivity, specificity and speed of the PCR test should make it a useful tool for detecting APX.


Assuntos
Apicomplexa/isolamento & purificação , Ostrea/virologia , Reação em Cadeia da Polimerase/métodos , Animais , Sequência de Bases , DNA/genética , Interações Hospedeiro-Parasita , Nova Zelândia , Sensibilidade e Especificidade
15.
Sci Rep ; 8(1): 12494, 2018 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-30131502

RESUMO

Bonamia ostreae has been associated with the decline of flat oyster Ostrea edulis populations in some European countries. This obligatory intracellular parasite persists and multiplies into hemocytes. Previous in vitro experiments showed that apoptosis is activated in hemocytes between 1 h and 4 h of contact with the parasite. The flat oyster uses the apoptosis pathway to defend against B. ostreae. However, the parasite might be also able to modulate this response in order to survive in its host. In order to investigate this hypothesis the apoptotic response of the host was evaluated using flow cytometry, transmission electron microscopy and by measuring the response of genes involved in the apoptotic pathway after 4 h. In parallel, the parasite response was investigated by measuring the expression of B. ostreae genes involved in different biological functions including cell cycle and cell death. Obtained results allow describing molecular apoptotic pathways in O. edulis and confirm that apoptosis is early activated in hemocytes after a contact with B. ostreae. Interestingly, at cellular and molecular levels this process appeared downregulated after 44 h of contact. Concurrently, parasite gene expression appeared reduced suggesting that the parasite could inhibit its own metabolism to escape the immune response.


Assuntos
Perfilação da Expressão Gênica/veterinária , Redes Reguladoras de Genes , Haplosporídios/patogenicidade , Ostrea/parasitologia , Animais , Apoptose , Ciclo Celular , Europa (Continente) , Citometria de Fluxo , Regulação da Expressão Gênica , Haplosporídios/genética , Hemócitos/parasitologia , Interações Hospedeiro-Parasita , Microscopia Eletrônica de Transmissão , Ostrea/genética , Análise de Sequência de RNA/veterinária
16.
J Environ Radioact ; 192: 376-384, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30048900

RESUMO

The uptake and depuration kinetics of dissolved 109Cd, 57Co and 134Cs were determined experimentally in the European flat oyster Ostrea edulis (Linnaeus, 1758) under different pH conditions (i.e., 8.1, 7.8 and 7.5) for 59 days. Uptake and depuration rates were variable within these elements; no effects were observed under different pH conditions for the uptake biokinetics of 109Cd and 57Co and depuration of 109Cd and 134Cs in oyster. The uptake and depuration rate constants of 134Cs differed during the exposure phase between treatments, while the steady state concentration factors (CFss) were similar. The resulting Cs activity that was purged during short- and long-term depuration phases differed, while the remaining activities after thirty-nine days depuration phase (RA39d) were similar. Co-57 depuration was affected by pCO2 conditions: RA39d were found to be significantly higher in oysters reared in normocapnia (pCO2 = 350 µatm) compared to high pCO2 conditions. Co-57 tissue distribution did not differ among the variable pCO2 conditions, while 109Cd and 134Cs accumulated in soft tissue of oysters were found to be higher under the highest pCO2. Additionally, Cd, Co and Cs were stored differently in various compartments of the oyster cells, i.e. cellular debris, metal-rich granules (MRG) and metallothionein-like proteins (MTLP), respectively. The subcellular sequestration of the elements at the end of the depuration phase did not differ among pH treatments. These results suggest that bioconcentration and tissue/subcellular distribution are element-specific in the oyster, and the effects of higher pCO2 driven acidification and/or coastal acidification variably influence these processes.


Assuntos
Radioisótopos de Cádmio/metabolismo , Radioisótopos de Césio/metabolismo , Radioisótopos de Cobalto/metabolismo , Ostrea/fisiologia , Poluentes Radioativos da Água/metabolismo , Animais , Radioisótopos de Cádmio/análise , Radioisótopos de Cádmio/química , Dióxido de Carbono/química , Radioisótopos de Césio/análise , Radioisótopos de Césio/química , Radioisótopos de Cobalto/análise , Radioisótopos de Cobalto/química , Concentração de Íons de Hidrogênio , Cinética , Metalotioneína/metabolismo , Oceanos e Mares , Água do Mar/química , Distribuição Tecidual , Poluentes Radioativos da Água/química
17.
Parasitology ; 145(11): 1483-1492, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29886855

RESUMO

Marteilia refringens causes marteiliosis in oysters, mussels and other bivalve molluscs. This parasite previously comprised two species, M. refringens and Marteilia maurini, which were synonymized in 2007 and subsequently referred to as M. refringens 'O-type' and 'M-type'. O-type has caused mass mortalities of the flat oyster Ostrea edulis. We used high throughput sequencing and histology to intensively screen flat oysters and mussels (Mytilus edulis) from the UK, Sweden and Norway for infection by both types and to generate multi-gene datasets to clarify their genetic distinctiveness. Mussels from the UK, Norway and Sweden were more frequently polymerase chain reaction (PCR)-positive for M-type (75/849) than oysters (11/542). We did not detect O-type in any northern European samples, and no histology-confirmed Marteilia-infected oysters were found in the UK, Norway and Sweden, even where co-habiting mussels were infected by the M-type. The two genetic lineages within 'M. refringens' are robustly distinguishable at species level. We therefore formally define them as separate species: M. refringens (previously O-type) and Marteilia pararefringens sp. nov. (M-type). We designed and tested new Marteilia-specific PCR primers amplifying from the 3' end of the 18S rRNA gene through to the 5.8S gene, which specifically amplified the target region from both tissue and environmental samples.


Assuntos
Cercozoários/classificação , Mytilus edulis/parasitologia , Ostrea/parasitologia , Infecções Protozoárias em Animais/epidemiologia , Animais , Sequenciamento de Nucleotídeos em Larga Escala , Noruega , Reação em Cadeia da Polimerase , RNA Ribossômico 18S/genética , Suécia , Reino Unido
18.
Dis Aquat Organ ; 128(2): 127-145, 2018 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-29733027

RESUMO

European flat oyster Ostrea edulis populations have suffered extensive mortalities caused by bonamiosis. The protozoan parasite Bonamia ostreae is largely responsible for this disease in Europe, while its congener B. exitiosa has been detected more recently in various European countries. Both of these intracellular parasites are able to survive and proliferate within haemocytes, the main cellular effectors of the immune system in molluscs. Two-dimensional electrophoresis was used to compare the haemolymph protein profile between Bonamia spp.-infected and non-infected oysters within 3 different stocks, a Galician stock of oysters selected for resistance against bonamiosis, a non-selected Galician stock and a selected Irish stock. Thirty-four proteins with a presumably relevant role in the oyster-Bonamia spp. interaction were identified; they were involved in major metabolic pathways, such as energy production, respiratory chain, oxidative stress, signal transduction, transcription, translation, protein degradation and cell defence. Furthermore, the haemolymph proteomic profiles of the non-infected oysters of the 2 Galician stocks were compared. As a result, 7 proteins representative of the non-infected Galician oysters selected for resistance against bonamiosis were identified; these 7 proteins could be considered as candidate markers of resistance to bonamiosis, which should be further assessed.


Assuntos
Haplosporídios/fisiologia , Hemolinfa/fisiologia , Ostrea/metabolismo , Ostrea/parasitologia , Animais , Regulação da Expressão Gênica , Hemócitos/metabolismo , Interações Hospedeiro-Parasita , Proteômica
19.
Sci Rep ; 8(1): 6080, 2018 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-29666427

RESUMO

Adaptive evolution and plasticity are two mechanisms that facilitate phenotypic differences between populations living in different environments. Understanding which mechanism underlies variation in fitness-related traits is a crucial step in designing conservation and restoration management strategies for taxa at risk from anthropogenic stressors. Olympia oysters (Ostrea lurida) have received considerable attention with regard to restoration, however there is limited information on adaptive population structure. Using oysters raised under common conditions for up to two generations (F1s and F2s), we tested for evidence of divergence in reproduction, larval growth, and juvenile growth among three populations in Puget Sound, Washington. We found that the population with the fastest growth rate also exhibited delayed and reduced reproductive activity, indicating a potential adaptive trade-off. Our results corroborate and extend upon a previous reciprocal transplant study on F1 oysters from the same populations, indicating that variation in growth rate and differences in reproductive timing are consistent across both natural and laboratory environments and have a strongly heritable component that cannot be entirely attributed to plasticity.


Assuntos
Ostrea/crescimento & desenvolvimento , Animais , Cruzamento , Ecossistema , Feminino , Variação Genética , Heterozigoto , Larva/genética , Larva/crescimento & desenvolvimento , Masculino , Ostrea/genética , Fenótipo , Crescimento Demográfico , Reprodução
20.
Genomics ; 110(6): 390-398, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29678683

RESUMO

European flat oyster (Ostrea edulis) production has suffered a severe decline due to bonamiosis. The responsible parasite enters in oyster haemocytes, causing an acute inflammatory response frequently leading to death. We used an immune-enriched oligo-microarray to understand the haemocyte response to Bonamia ostreae by comparing expression profiles between naïve (NS) and long-term affected (AS) populations along a time series (1 d, 30 d, 90 d). AS showed a much higher response just after challenge, which might be indicative of selection for resistance. No regulated genes were detected at 30 d in both populations while a notable reactivation was observed at 90 d, suggesting parasite latency during infection. Genes related to extracellular matrix and protease inhibitors, up-regulated in AS, and those related to histones, down-regulated in NS, might play an important role along the infection. Twenty-four candidate genes related to resistance should be further validated for selection programs aimed to control bonamiosis.


Assuntos
Haplosporídios , Hemócitos/metabolismo , Ostrea/genética , Infecções por Protozoários/genética , Transcriptoma , Animais , Regulação da Expressão Gênica , Hemócitos/imunologia , Ostrea/imunologia , Ostrea/metabolismo , Infecções por Protozoários/metabolismo
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