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Boullot, Floriane; Castrec, Justine; Bidault, Adeline; Dantas, Natanael; Payton, Laura; Perrigault, Mickael; Tran, Damien; Amzil, Zouher; Boudry, Pierre; Soudant, Philippe; Hegaret, Helene; Fabioux, Caroline. |
Paralytic shellfish toxins (PST) bind to voltage-gated sodium channels (Nav) and block conduction of action potential in excitable cells. This study aimed to (i) characterize Nav sequences in Crassostrea gigas and (ii) investigate a putative relation between Nav and PST-bioaccumulation in oysters. The phylogenetic analysis highlighted two types of Nav in C. gigas: a Nav1 (CgNav1) and a Nav2 (CgNav2) with sequence properties of sodium-selective and sodium/calcium-selective channels, respectively. Three alternative splice transcripts of CgNav1 named A, B and C, were characterized. The expression of CgNav1, analyzed by in situ hybridization, is specific to nervous cells and to structures corresponding to neuromuscular junctions. Real-time PCR analyses showed... |
Tipo: Text |
Palavras-chave: Crassostrea gigas; Sodium channel; Alternative splicing; Alexandrium minutum; Paralytic shellfish toxins. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00368/47877/47892.pdf |
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Berge, Jorgen; Daase, Malin; Renaud, Paul E.; Ambrose, William G., Jr.; Darnis, Gerald; Last, Kim S.; Leu, Eva; Cohen, Jonathan H.; Johnsen, Geir; Moline, Mark A.; Cottier, Finlo; Varpe, Oystein; Shunatova, Natalia; Balazy, Piotr; Morata, Nathalie; Massabuau, Jean-charles; Falk-petersen, Stig; Kosobokova, Ksenia; Hoppe, Clara J. M.; Weslawski, Jan Marcin; Kuklinski, Piotr; Legezynska, Joanna; Nikishina, Daria; Cusa, Marine; Kedra, Monika; Wlodarska-kowalczuk, Maria; Vogedes, Daniel; Camus, Lionel; Tran, Damien; Michaud, Emma; Gabrielsen, Tove M.; Granovitch, Andrei; Gonchar, Anya; Krapp, Rupert; Callesen, Trine A.. |
The current understanding of Arctic ecosystems is deeply rooted in the classical view of a bottom-up controlled system with strong physical forcing and seasonality in primary-production regimes. Consequently, the Arctic polar night is commonly disregarded as a time of year when biological activities are reduced to a minimum due to a reduced food supply. Here, based upon a multidisciplinary ecosystem-scale study from the polar night at 79 degrees N, we present an entirely different view. Instead of an ecosystem that has entered a resting state, we document a system with high activity levels and biological interactions across most trophic levels. In some habitats, biological diversity and presence of juvenile stages were elevated in winter months compared to... |
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Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00288/39885/38620.pdf |
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Payton, Laura; Perrigault, Mickael; Hoede, Claire; Massabuau, Jean-charles; Sow, Mohamedou; Huvet, Arnaud; Boullot, Floriane; Fabioux, Caroline; Hegaret, Helene; Tran, Damien. |
As a marine organism, the oyster Crassostrea gigas inhabits a complex biotope governed by interactions between the moon and the sun cycles. We used next-generation sequencing to investigate temporal regulation of oysters under light/dark entrainment and the impact of harmful algal exposure. We found that ≈6% of the gills’ transcriptome exhibits circadian expression, characterized by a nocturnal and bimodal pattern. Surprisingly, a higher number of ultradian transcripts were also detected under solely circadian entrainment. The results showed that a bloom of Alexandrium minutum generated a remodeling of the bivalve’s temporal structure, characterized by a loss of oscillations, a genesis of de novo oscillating transcripts, and a switch in the period of... |
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Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00389/50008/50595.pdf |
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Haberkorn, Hansy; Tran, Damien; Massabuau, Jean-charles; Ciret, Pierre; Savar, Veronique; Soudant, Philippe. |
The complexity of the relationships between Alexandrium minutum (Am.) concentration in the water ([A.m.](w)), Paralytic Shellfish Poisoning contamination in the digestive gland ([PSP](dg)) and valve behavior was explored in oysters Crassostrea gigas. Two experiments were conducted, during which oysters' valve behaviour were analyzed. Oysters, first acclimated for 10-days with the non harmful microalgae Heterocapsa triquetra (H.t.), were exposed to four microalgae mixtures at constant total concentrations of 10 x 10(3) cells ml(-1) (experiment-1) and 5 x 10(3) cells ml(-1) (experiment-2): 100% Am.; 50% A.m.-50% H.t.; 25% A.m.-75% H.t.; 100% H.t. At the end of experiment-2, [PSP](dg) were measured. At 10 x 103 cells ml(-1), the microalgal ingestion decreased... |
Tipo: Text |
Palavras-chave: Harmful algae; Oysters; Behavioral responses; Algae concentration; Toxin accumulation. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00041/15195/12617.pdf |
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