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Registros recuperados: 10 | |
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Duvic, B.; Jouan, V.; Essa, N.; Girard, P-a; Pages, S.; Khattar, Z. Abi; Volkoff, N-a; Givaudan, A.; Destoumieux-garzon, Delphine; Escoubas, Jean-michel. |
An antimicrobial peptide (AMP) of the cecropin family was isolated by HPLC from plasma of the insect pest, Spodoptera frugiperda. Its molecular mass is 3910.9 Da as determined by mass spectrometry. Thanks to the EST database Spodobase, we were able to describe 13 cDNAs encoding six different cecropins which belong to the sub-families CecA, CecB, CecC and CecD. The purified peptide identified as CecB1 was chemically synthesized (syCecB1). It was shown to be active against Gram-positive and Gram-negative bacteria as well as fungi. Two closely related entomopathogenic bacteria, Xenorhabdus nematophila F1 and Xenorhabdus mauleonii VC01(T) showed different susceptibility to syCecB1. Indeed, X. nematophila was sensitive to syCecB1 whereas X. mauleonii had a... |
Tipo: Text |
Palavras-chave: Humoral immunity; Innate immunity; Immunosuppression; Lepidopteran; Invertebrate. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00086/19728/17485.pdf |
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Chapuis, E.; Emelianoff, V.; Paulmier, V.; Le Brun, N.; Pages, S.; Sicard, M.; Ferdy, J.B.. |
Coevolution in mutualistic symbiosis can yield, because the interacting partners share common interests, to coadaptation: hosts perform better when associated with symbionts of their own locality than with others coming from more distant places. However, as the two partners of a symbiosis might also experience conflicts over part of their life cycle, coadaptation might not occur for all life-history traits. We investigated this issue in symbiotic systems where nematodes (Steinernema) and bacteria (Xenorhabdus) reproduce in insects they have both contributed to kill. Newborn infective juveniles (IJs) that carry bacteria in their intestine then disperse from the insect cadaver in search of a new host to infect. We ran experiments where nematodes coinfect... |
Tipo: Journal Article |
Palavras-chave: COADAPTATION; MUTUALISM; SPECIFICITY; STEINERNEMA; XENORHABDUS. |
Ano: 2009 |
URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD2011a41bb11e&uri=/notices/prodinra1/2011/05/ |
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Gaudriault, S.; Pages, S.; Lanois, A.; Laroui, C.; Teyssier, C.; Jumas-Bilak, E.; Givaudan, A.. |
Background: The phenotypic consequences of large genomic architecture modifications within a clonal bacterial population are rarely evaluated because of the difficulties associated with using molecular approaches in a mixed population. Bacterial variants frequently arise among Photorhabdus luminescens, a nematode-symbiotic and insect-pathogenic bacterium. We therefore studied genome plasticity within Photorhabdus variants.Results: We used a combination of macrorestriction and DNA microarray experiments to perform a comparative genomic study of different P. luminescens TT01 variants. Prolonged culturing of TT01 strain and a genomic variant, collected from the laboratory-maintained symbiotic nematode, generated bacterial lineages composed of primary and... |
Tipo: Journal Article |
Palavras-chave: PHOTORHABDUS; NEMATODE-SYMBIOTIC; INSECT-PATHOGENIC BACTERIUM; BACTERIAL GENOME ARCHITECTURE; PHENOTYPIC VARIANT. |
Ano: 2008 |
URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD201041309cda&uri=/notices/prodinra1/2010/10/ |
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Varela Chavez, C.; Jubelin, G.; Courties, G.; Gomard, A.; Ginibre, N.; Pages, S.; Taieb, F.; Girard, P.A.; Oswald, E.; Givaudan, A.; Zumbihl, R.; Escoubas, J.M.. |
Cycle inhibiting factors (Cif) constitute a broad family of cyclomodulins present in bacterial pathogens of invertebrates and mammals. Cif proteins are thought to be type III effectors capable of arresting the cell cycle at G2/M phase transition in human cell lines. We report here the first direct functional analysis of CifPl, from the entomopathogenic bacterium Photorhabdus luminescens, in its insect host. The cifPl gene was expressed in P. luminescens cultures in vitro. The resulting protein was released into the culture medium, unlike the well characterized type III effector LopT. During locust infection, cifPl was expressed in both the hemolymph and the hematopoietic organ, but was not essential for P. luminescens virulence. CifPl inhibited... |
Tipo: Journal Article |
Palavras-chave: PHOTORHABDUS; APOPTOSIS; CYCLE INHIBITING FACTOR; CIF; TYPE III SECRETION SYSTEM. |
Ano: 2010 |
URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD20119b3aacae&uri=/notices/prodinra1/2011/05/ |
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Derzelle, S.; Turlin, E.; Duchaud, E.; Pages, S.; Kunst, F.; Givaudan, A.; Danchin, A.. |
Photorhabdus luminescens is a symbiont of entomopathogenic nematodes. Analysis of the genome sequence of this organism revealed a homologue of PhoP-PhoQ, a two-component system associated with virulence in intracellular bacterial pathogens. This organism was shown to respond to the availability of environmental magnesium. A mutant with a knockout mutation in the regulatory component of this system (phoP) had no obvious growth defect. It was, however, more motile and more sensitive to antimicrobial peptides than its wild-type parent. Remarkably, the mutation eliminated virulence in an insect model. No insect mortality was observed after injection of a large number of the phoP bacteria, while very small amounts of parental cells killed insect larvae in less... |
Tipo: Journal Article |
Palavras-chave: ENTOMOPATHOGENIC NEMATODE; GENOME SEQUENCE; BACTERIAL PATHOGENE; VIRULENCE; INSECT MODEL; MAGNESIUM. |
Ano: 2004 |
URL: http://www.prodinra.inra.fr/prodinra/pinra/doc.xsp?id=PROD2008acbe701f&uri=/notices/prodinra1/2009/03/ |
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Registros recuperados: 10 | |
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