Consulta: creatorFacets:"Malo, Florent"
Registros recuperados: 10
Data/hora: 01/06/2024 04:41:36

pH controls spermatozoa motility in the Pacific oyster (     Crassostrea gigas     )
Provedor de dados: 5
Autores: Boulais, Myrina; Suquet, Marc; Arsenault-pernet, Marie Eve Julie; Malo, Florent; Queau, Isabelle; Pignet, Patricia; Ratiskol, Dominique; Le Grand, Jacqueline; Huber, Matthias; Cosson, Jacky.
Investigating the roles of chemical factors stimulating and inhibiting sperm motility is required to understand the mechanisms of spermatozoa movement. In this study, we described the composition of the seminal fluid (osmotic pressure, pH, and ions) and investigated the roles of these factors and salinity in initiating spermatozoa movement in the Pacific oyster. The acidic pH of the gonad (5.82 ± 0.22) maintained sperm in the quiescent stage and initiation of flagellar movement was triggered by a sudden increase of spermatozoa external pH (pHe) when released in seawater (SW). At pH 6.4, percentage of motile spermatozoa was three times higher when they were activated in SW containing 30 mM NH4Cl, which alkalinizes internal pH (pHi) of spermatozoa, compared...
Tipo: Text
Palavras-chave: Seminal fluid; Spermatozoa; Motility; PH; Salinity; Ions.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00428/53976/55137.pdf

Combined effects of temperature, irradiance and pH on   Teleaulax amphioxeia   (Cryptophyceae) physiology and feeding ratio for its predator   Mesodinium rubrum   (Ciliophora)
Provedor de dados: 5
Autores: Gaillard, Sylvain; Charrier, Aurelie; Malo, Florent; Carpentier, Liliane; Bougaran, Gael; Hégaret, Helene; Réveillon, Damien; Hess, Philipp; Séchet, Veronique.
The cryptophyte Teleaulax amphioxeia is a source of plastids for the ciliate Mesodinium rubrum and both organisms are members of the trophic chain of several species of Dinophysis. It is important to better understand the ecology of organisms at the first trophic levels before assessing the impact of principal factors of global change on Dinophysis spp. Therefore, combined effects of temperature, irradiance and pH on growth rate, photosynthetic activity and pigment content of a temperate strain of T. amphioxeia were studied using a full factorial design (central composite design 23*) in 17 individually controlled bioreactors. The derived model predicted an optimal growth rate of T. amphioxeia at a light intensity of 400 µmol photons · m‐2 · s‐1, more...
Tipo: Text
Palavras-chave: Dinophysis; Ecophysiology; Full factorial design; Global change; Mesodinium rubrum; Teleaulax amphioxeia.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00609/72155/70910.pdf

Optimizing sperm cryopreservation in great scallop (Pecten maximus)
Provedor de dados: 5
Autores: Suquet, Marc; Malo, Florent; Gourtay, Clemence; Ratiskol, Dominique; Riobe, Marion; Le Grand, Jacqueline; Queau, Isabelle; Mingant, Christian.
A basic cryopreservation protocol for great scallop sperm was recently published, with which thawed sperm survival remained limited to 25% of control values (Suquet et al. 2014). We designed here a set of five experiments to test ways of improving thawed sperm survival and storage by studying the effects of (1) cryoprotectant concentration; (2) sugar incorporation in the extender; (3) egg yolk addition to the extender; (4) sperm dilution rate; and (5) storage capacity of thawed sperm at 4 degrees C. A sixth experiment was then performed to compare rearing performances of larvae produced using thawed sperm from the optimal protocol defined in the present study with those produced using fresh sperm. During the first experiment, a significantly higher...
Tipo: Text
Palavras-chave: Pecten maximus; Mollusc; Sperm; Cryopreservation; Larval rearing.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00359/47033/46946.pdf

Seasonal variation of sperm quality in Pacific oyster (Crassostrea gigas)
Provedor de dados: 5
Autores: Suquet, Marc; Malo, Florent; Queau, Isabelle; Ratiskol, Dominique; Quere, Claudie; Le Grand, Jacqueline; Fauvel, Christian.
Seasonal changes of sperm quality which can affect sperm biological parameters throughout the breeding period, have been little studied in mollusc species. Controlling gamete quality would aid the management of gametes in hatcheries and the development of selection programs. The aim of the present study was to describe the changes in sperm quality of wild Pacific oysters through the spawning season by comparing sperm parameters at the beginning (May), middle (July) and end (October) of this period using a panel of bio-descriptors. These parameters were studied over the 2014 breeding season based on shed sperm collected after serotonin injection of wild breeders. A significantly higher percentage of motile sperm was observed at the end of the spawning...
Tipo: Text
Palavras-chave: Crassostrea gigas; Sperm quality; Sperm ageing; Season; Motility.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00346/45690/45310.pdf

From the sxtA4 Gene to Saxitoxin Production: What Controls the Variability Among Alexandrium minutum and Alexandrium pacificum Strains?
Provedor de dados: 5
Autores: Geffroy, Solene; Lechat, Marc-marie; Le Gac, Mickael; Rovillon, Georges-augustin; Marie, Dominique; Bigeard, Estelle; Malo, Florent; Amzil, Zouher; Guillou, Laure; Caruana, Amandine.
Paralytic shellfish poisoning (PSP) is a human foodborne syndrome caused by the consumption of shellfish that accumulate paralytic shellfish toxins (PSTs, saxitoxin group). In PST-producing dinoflagellates such as Alexandrium spp., toxin synthesis is encoded in the nuclear genome via a gene cluster (sxt). Toxin production is supposedly associated with the presence of a 4th domain in the sxtA gene (sxtA4), one of the core genes of the PST gene cluster. It is postulated that gene expression in dinoflagellates is partially constitutive, with both transcriptional and post-transcriptional processes potentially co-occurring. Therefore, gene structure and expression mode are two important features to explore in order to fully understand toxin production processes...
Tipo: Text
Palavras-chave: Alexandrium; Saxitoxins; SxtA4; Copy number variation; SxtA; Expression; Isoform.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00682/79402/81944.pdf

Influence of temperature, irradiance and pH on the physiology of Teleaulax amphioxeia
Provedor de dados: 5
Autores: Gaillard, Sylvain; Charrier, Aurelie; Carpentier, Liliane; Malo, Florent; Bougaran, Gael; Hegaret, Helene; Hess, Philipp; Sechet, Veronique.
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00617/72958/71990.pdf

Aquaculture of microalgae in New-Caledonia. AMICAL
Provedor de dados: 5
Autores: Coulombier, Noemie; Chim, Liet; Le Dean, Loic; Morezzi, Nicola; Brun, Pierre; Malo, Florent; Nakagawa, Kento; Ducrocq, Manuel; Rivaton, Adrien; Colin, Fabrice.
AMICAL is a partnership program of research and innovation between ADECAL TECHNOPOLE (New Caledonia innovation and technology park) and IFREMER to initiate the development of a microalgae industry in New Caledonia, based on selected local strains. This French oversea territory, located in south Pacific, features many competitive advantages for the development of a blue economy industry (climate, biodiversity hotspot, well developed aquaculture sector...). The project relies on two laboratories (Figure 1) owned and managed by ADECAL TECHNOPOLE with the scientific support of IFREMER:  • the Laboratory for MicroAlgae study (LEMA), whose scientific direction is provided by the laboratory of Physiology and Biotechnology of Algae (PBA, IFREMER, Nantes),...
Tipo: Text
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00358/46897/46783.pdf

Gamete quality in triploid Pacific oyster (Crassostrea gigas)
Provedor de dados: 5
Autores: Suquet, Marc; Malo, Florent; Quere, Claudie; Ledu, Christophe; Le Grand, Jacqueline; Benabdelmouna, Abdellah.
Triploidy induction in shellfish aims to obtain faster growth and sterility of reared individuals. Triploid Pacific oysters are most often not totally sterile, but have greatly reduced reproductive capacities compared to those recorded in diploid individuals. The description of gamete output in triploid aquatic animals is most often confined to the assessment of fecundity in females. The present work aims at further describing gamete quality of triploid Pacific oysters and comparing it to values observed in diploid individuals. Diploid and triploid oysters (produced by mating tetraploid males × diploid females) were reared in standard conditions and then transferred to the wild to allow the offspring to attain reproductive maturity. At the end of...
Tipo: Text
Palavras-chave: Crassostrea gigas; Reproduction; Triploidy; Gamete.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00277/38835/37581.pdf

The quality of great scallop (Pecten maximus) sperm after thawing
Provedor de dados: 5
Autores: Suquet, Marc; Gourtay, Clemence; Donval, Anne; Le Goic, Nelly; Quere, Claudie; Malo, Florent; Le Grand, Jacqueline; Ratiskol, Dominique; Mingant, Christian; Fauvel, Christian.
Most publications devoted to the cryopreservation of mollusc sperm have focused on the definition of technical protocols, avoiding the description of sperm quality after thawing. The present study investigated the effects of cryopreservation on sperm quality in the great scallop. Wild scallop were fished during the natural spawning period and conditioned in the hatchery before use. Sperm samples were obtained after intragonadal injection of serotonin and cryopreserved using a previously published protocol.  Sperm quality was assessed using a panel of four parameters: sperm motility characteristics, using a a computer assisted sperm analysis plugin with Image J, intracellular ATP content using an ATP-Lite kit, sperm integrity, using flow cytometry and sperm...
Tipo: Text
Palavras-chave: Pecten maximus; Reproduction; Gamete; Sperm; Cryopreservation.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00317/42862/43912.pdf

Characterization of toxin-producing strains of Dinophysis spp. (Dinophyceae) isolated from French coastal waters, with a particular focus on the D. acuminata-complex
Provedor de dados: 5
Autores: Séchet, Veronique; Sibat, Manoella; Bilien, Gwenael; Carpentier, Liliane; Rovillon, Georges-augustin; Raimbault, Virginie; Malo, Florent; Gaillard, Sylvain; Perrière-rumebe, Myriam; Hess, Philipp; Chomérat, Nicolas.
Dinoflagellates of the genus Dinophysis are the most prominent producers of Diarrhetic Shellfish Poisoning (DSP) toxins which have an impact on public health and on marine aquaculture worldwide. In particular, Dinophysis acuminata has been reported as the major DSP agent in Western Europe. Still, its contribution to DSP events in the regions of the English Channel and the Atlantic coast of France, and the role of the others species of the Dinophysis community in these areas are not as clear. In addition, species identification within the D. acuminata complex has proven difficult due to their highly similar morphological features. In the present study, 30 clonal strains of the dominant Dinophysis species have been isolated from French coasts including the...
Tipo: Text
Palavras-chave: Dinophysis spp; . Phylogeny; Taxonomy; Toxin profiles.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00679/79081/81880.pdf