Consulta: creatorFacets:"Delsert, Claude"
Registros recuperados: 13
Data/hora: 10/06/2024 14:01:47

Adult somatic progenitor cells and hematopoiesis in oysters
Provedor de dados: 5
Autores: Jemaa, Mohamed; Morin, Nathalie; Cavelier, Patricia; Cau, Julien; Strub, Jean Marc; Delsert, Claude.
Long-lived animals show a non-observable age-related decline in immune defense, which is provided by blood cells that derive from self-renewing stem cells. The oldest living animals are bivalves. Yet, the origin of hemocytes, the cells involved in innate immunity, is unknown in bivalves and current knowledge about mollusk adult somatic stem cells is scarce. Here we identify a population of adult somatic precursor cells and show their differentiation into hemocytes. Oyster gill contains an as yet unreported irregularly folded structure (IFS) with stem-like cells bathing into the hemolymph. BrdU labeling revealed that the stem-like cells in the gill epithelium and in the nearby hemolymph replicate DNA. Proliferation of this cell population was further...
Tipo: Text
Palavras-chave: Hematopoiesis; Adult somatic progenitor cells; Hemocytes; Mollusk; Marine invertebrates.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00197/30802/29172.pdf

Fish nodavirus lytic cycle and semipermissive expression in mammalian and fish cell cultures
Provedor de dados: 5
Autores: Delsert, Claude; Morin, Nathalie; Comps, Michel.
In this study, Dicentrarchus labrax encephalitis virus (DIEV), which causes sea bass encephalitis, was propagated in cell culture, thus allowing study of its lytic cycle, DIEV infection of mammalian and fish cells induced different patterns of expression of capsid proteins, which were assembled as virus-like particles, accumulating in the cytoplasm either as diffuse masses or in vesicles, as shown by electron microscopy, These particles correspond to virions, as shown by their ability to induce Secondary infection, Fish cells proved to be more permissive for DIEV than mammalian cells, although virus yield remained low, RNA analysis of infected sea bass cells revealed DIEV RNA3, in addition to genomic RNA1 and RNA2, and the presence of the RNA;! minus...
Tipo: Text
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00336/44697/44983.pdf

Etude du virus de type herpes observé chez les huîtres
Provedor de dados: 5
Autores: Le Deuff, Rose-marie; Lipart, Cecile; Chollet, Bruno; Haffner, Philippe; Delsert, Claude; Cochennec, Nathalie; Renault, Tristan.
Since 1991, sporadic, but high mortality in larvae of the Pacific oyster (Crassostrea gigas) has been observed during the summer in various French hatcheries. This mortality was concomitant with the detection of a virus by transmission electron microscopy. This virus, by virtue of its morphological characteristics and developmental cycle, seems to belong to the Herpesviridae family. The pathogenicity of this viral agent has been demonstrated in the laboratory by experimentally induced mortality on healthy larvae. Moreover, concomitant mortality has been reported in larvae of Crassostrea gigas and Ostrea edulis reared in the same tanks, with detection of a herpes-type virus.
Tipo: Text
Palavras-chave: Virus; Herpeviridae; Pathologie; Crassostrea gigas.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/1997/acte-3248.pdf

Microtubule polyglutamylation and acetylation drive microtubule dynamics critical for platelet formation
Provedor de dados: 5
Autores: Van Dijk, Juliette; Bompard, Guillaume; Cau, Julien; Kunishima, Shinji; Rabeharivelo, Gabriel; Mateos-langerak, Julio; Cazevieille, Chantal; Cavelier, Patricia; Boizet-bonhoure, Brigitte; Delsert, Claude; Morin, Nathalie.
Background Upon maturation in the bone marrow, polyploid megakaryocytes elongate very long and thin cytoplasmic branches called proplatelets. Proplatelets enter the sinusoids blood vessels in which platelets are ultimately released. Microtubule dynamics, bundling, sliding, and coiling, drive these dramatic morphological changes whose regulation remains poorly understood. Microtubule properties are defined by tubulin isotype composition and post-translational modification patterns. It remains unknown whether microtubule post-translational modifications occur in proplatelets and if so, whether they contribute to platelet formation. Results Here, we show that in proplatelets from mouse megakaryocytes, microtubules are both acetylated and polyglutamylated. To...
Tipo: Text
Palavras-chave: Microtubules; Acetylation; Polyglutamylation; Tubulin isotype; Platelets; Megakaryocytes; IIb3 integrin; CHO cells.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00463/57463/59577.pdf

Variable microsatellites in the Pacific Oyster Crassostrea gigas and other cupped oyster species
Provedor de dados: 5
Autores: Huvet, Arnaud; Boudry, Pierre; Ohresser, M; Delsert, Claude; Bonhomme, F.
Source/description : Genomic DNA was extracted from a whole Pacific oyster (C. gigas) after grinding in liquid nitrogen. Purified DNA was then digested by a mix of 3 restriction enzymes (AluI, RsaI, HaeIII). DNA fragments ranging from 250 to 500 bp were size-selected by agarose gel electrophoresis and ligated into the dephosphorylated blunt-ended SmaI-linearised pBKS2 plasmid (Stratagene Cloning System, CA). White colonies (11,500) were screened by hybridisation with double-stranded DNA probes containing dinucleotide repeats. Poly(dAdC), poly(dAdG), poly(dAdT) (Pharmacia Biotech, Sweden) were mixed at equimolar ratio and radiolabelled by [&amp;#61537;-32P] alpha dATP and dCTP using a random priming labelling kit (Life Technologies, Germany). Filter...
Tipo: Text
Palavras-chave: Crassostrea gigas; Oyster; Microsatellites.
Ano: 2000
URL: http://archimer.ifremer.fr/doc/2000/publication-703.pdf

Tumorhead distribution to cytoplasmic membrane of neural plate cells is positively regulated by Xenopus p21-activated kinase 1 (X-PAK1)
Provedor de dados: 5
Autores: Wu, Chuan-fen; Delsert, Claude; Faure, Sandrine; Traverso, Edwin E.; Kloc, Malgorzata; Kuang, Jian; Etkin, Laurence D.; Morin, Nathalie.
Tumorhead (TH) regulates neural plate cell proliferation during Xenopus early development, and gain or loss of function prevents neural differentiation. TH shuttles between the nuclear and cytoplasmic/cortical cell compartments in embryonic cells. In this study, we show that subcellular distribution of TH is important for its functions. Targeting TH to the cell cortex/membrane potentiates a TH gain of function phenotype and results in neural plate expansion and inhibition of neuronal differentiation. We have found that TH subcellular localization is regulated, and that its shuttling between the nucleus and the cell cortex/cytoplasm is controlled by the catalytic activity of p21-activated kinase, X-PAK1. The phenotypes of embryos that lack, or have excess,...
Tipo: Text
Palavras-chave: Actin cytoskeleton; Differentiation; Proliferation; Neural plate; P21 activated kinase; Tumorhead.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2996.pdf

Development of mussel-specific expression vectors suitable for transgenic organisms: implication on the establishment of mollusc continuous cell lines
Provedor de dados: 5
Autores: Delsert, Claude; Cancela Da Fonseca, Leonor.
The main objective of this project was to develop the tools for the in-depth understanding of mollusc biology and pathology. Such a goal has been reached in other biological systems through the development of molecular biology and cell culture. Indeed, development of a mollusc cell culture system is an essential step to approach many of the problems related to mollusc pathology, in particular to use molecular biology tools to study viral infection of these organisms. No continous cell line is available from bivalves and while cell cultures have been obtained from these organisms they are difficult to develop and labor intensive, survival cultures being maintained only for a few weeks. Our goal has been to study in detail many of the parameters involved in...
Tipo: Text
Palavras-chave: Pathology; Mussel-specific expression vectors; Cell culture; Mytilus galloprovincialis; Gene; Genetic marker.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00044/15540/12917.pdf

Early gametogenesis in the Pacific oyster: new insights using stem cell and mitotic markers
Provedor de dados: 5
Autores: Cavelier, Patricia; Cau, Julien; Morin, Nathalie; Delsert, Claude.
While our knowledge of bivalve gametogenesis has progressed in recent times, more molecular markers are needed in order to develop tissue imaging. Here, we identified stem cell and mitotic markers to further characterize oyster early gametogenesis, mainly through immunofluorescence microscopy. Intense alkaline phosphatase activity, a non-specific marker for stem cells, was detected on the outer edge of the gonad ducts at the post-spawning stage, suggesting an abundance of undifferentiated cells very early during the sexual cycle. This observation was confirmed using an antibody against Sox2, a transcription factor specific for stem or germline cells, which labeled cells in the gonad duct inner mass and ciliated epithelium early during the initial oyster...
Tipo: Text
Palavras-chave: Germline cells; Cell cycle; Reproduction; Bivalve; Marine invertebrates.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00409/52100/52809.pdf

Metalloprotease Vsm Is the Major Determinant of Toxicity for Extracellular Products of Vibrio splendidus
Provedor de dados: 5
Autores: Binesse, J; Delsert, Claude; Saulnier, Denis; Champomier Verges, M; Zagorec, M; Munier Lehmann, H; Mazel, D; Le Roux, F.
Genomic data combined with reverse genetic approaches have contributed to the characterization of major virulence factors of Vibrio species; however, these studies have targeted primarily human pathogens. Here, we investigate virulence factors in the oyster pathogen Vibrio splendidus LGP32 and show that toxicity is correlated to the presence of a metalloprotease and its corresponding vsm gene. Comparative genomics showed that an avirulent strain closely related to LGP32 lacked the metalloprotease. The toxicity of LGP32 metalloprotease was confirmed by exposing mollusk and mouse fibroblastic cell lines to extracellular products (ECPs) of the wild type (wt) and a vsm deletion mutant (Delta vsm mutant). The ECPs of the wt induced a strong cytopathic effect...
Tipo: Text
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4931.pdf

Acclimatation de nouvelles espèces d'huîtres creuses du genre Crassostrea: hybridations et conservatoire de souches. Contrat de Plan Etat Région Poitou- Charentes 1994-1998 - Convention 95/RPC-R-57 "Génétique" - Rapport année 1995
Provedor de dados: 5
Autores: Boudry, Pierre; Naciri, Yamama; Heurtebise, Serge; Delsert, Claude; Ledu, Christophe; Phelipot, Pascal; Chollet, Bruno; Cochennec, Nathalie; Gerard, Andre.
Le laboratoire IFREMER "Génétique Aquaculture et Pathologie" (GAP) (La Tremblade et Bouin) a entrepris des actions de recherche sur ces différents points. L'Unité de Recherche en Génétique, en collaboration avec tous les membres du Réseau Génétique Mollusques (REGEMO), a axé une partie de ses travaux sur l'acclimatation et l'hybridation de différentes espèces du genre Crassostrea. Ces recherches ont débuté avec le soutien du Conseil Général de Charente-Maritime depuis 1992 sur des essais d'acclimatation de C. virginica, l'huître creuse américaine. En prolongement de cette étude, l'URGE a proposé à la région Poitou-Charentes un programme de recherche plus vaste sur l'ensemble des espèces d'huîtres creuses.
Tipo: Text
Palavras-chave: Génétique; Acclimatation; Hybridation; Crassostrea virgnica.
Ano: 1995
URL: http://archimer.ifremer.fr/doc/00044/15515/12902.pdf

P21-activated kinase 4 (PAK4) is required for metaphase spindle positioning and anchoring
Provedor de dados: 5
Autores: Bompard, G.; Rabeharivelo, G.; Cau, J.; Abrieu, A.; Delsert, Claude; Morin, N.
The oncogenic kinase PAK4 was recently found to be involved in the regulation of the G1 phase and the G2/M transition of the cell cycle. We have also identified that PAK4 regulates Ran GTPase activity during mitosis. Here, we show that after entering mitosis, PAK4-depleted cells maintain a prolonged metaphase-like state. In these cells, chromosome congression to the metaphase plate occurs with normal kinetics but is followed by an extended period during which membrane blebbing and spindle rotation are observed. These bipolar PAK4-depleted metaphase-like spindles have a defective astral microtubule MT network and are not centered in the cell but are in close contact with the cell cortex. As the metaphase-like state persists, centrosome fragmentation occurs,...
Tipo: Text
Palavras-chave: P21-activated kinase 4; Metaphase; Spindle orientation; Spindle assembly checkpoint.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00133/24465/22502.pdf

PAK1 Regulates MEC-17 Acetyltransferase Activity and Microtubule Acetylation during Proplatelet Extension
Provedor de dados: 5
Autores: Van Dijk, Juliette; Bompard, Guillaume; Rabeharivelo, Gabriel; Cau, Julien; Delsert, Claude; Morin, Nathalie.
Mature megakaryocytes extend long processes called proplatelets from which platelets are released in the blood stream. The Rho GTPases Cdc42 and Rac as well as their downstream target, p21-activated kinase 2 (PAK2), have been demonstrated to be important for platelet formation. Here we address the role, during platelet formation, of PAK1, another target of the Rho GTPases. PAK1 decorates the bundled microtubules (MTs) of megakaryocyte proplatelets. Using a validated cell model which recapitulates proplatelet formation, elongation and platelet release, we show that lack of PAK1 activity increases the number of proplatelets but restrains their elongation. Moreover, in the absence of PAK1 activity, cells have hyperacetylated MTs and lose their MT network...
Tipo: Text
Palavras-chave: Microtubules; Acetylation; Megakaryocytes; Proplatelet; P21-activated kinase 1 PAK1; Acetyltransferase MEC-17.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00654/76594/77743.pdf

Subgroup II PAK-mediated phosphorylation regulates Ran activity during mitosis
Provedor de dados: 5
Autores: Bompard, Guillaume; Rabeharivelo, Gabriel; Frank, Marie; Cau, Julien; Delsert, Claude; Morin, Nathalie.
Ran is an essential GTPase that controls nucleocytoplasmic transport, mitosis, and nuclear envelope formation. These functions are regulated by interaction of Ran with different partners, and by formation of a Ran-GTP gradient emanating from chromatin. Here, we identify a novel level of Ran regulation. We show that Ran is a substrate for p21-activated kinase 4 (PAK4) and that its phosphorylation on serine-135 increases during mitosis. The endogenous phosphorylated Ran and active PAK4 dynamically associate with different components of the microtubule spindle during mitotic progression. A GDP-ound Ran phosphomimetic mutant cannot undergo RCC1-mediated GDP/GTP exchange and cannot induce microtubule asters in mitotic Xenopus egg extracts. Conversely,...
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00014/12502/9353.pdf