Search results for "Bios"
showing 10 items of 2557 documents
Parasite-induced alteration of plastic response to predation threat: increased refuge use but lower food intake in Gammarus pulex infected with the a…
2014
6 pages; International audience; Larvae of many trophically-transmitted parasites alter the behaviour of their intermediate host in ways that increase their probability of transmission to the next host in their life cycle. Before reaching a stage that is infective to the next host, parasite larvae may develop through several larval stages in the intermediate host that are not infective to the definitive host. Early predation at these stages results in parasite death, and it has recently been shown that non-infective larvae of some helminths decrease such risk by enhancing the anti-predator defences of the host, including decreased activity and increased sheltering. However, these behavioura…
Host plant cultivar of the grapevine moth Lobesia botrana affects the life history traits of an egg parasitoid.
2009
6 pages; International audience; The quality and susceptibility of insect eggs for egg parasitoids may be affected by the diet experienced by the females that produce the host eggs. We tested the hypothesis that the host plant fed upon by an herbivore during the larval stages will determine the quality of the eggs laid by the adult for an egg parasitoid. We used the tritrophic system comprising five grape cultivars, the European grapevine moth, Lobesia botrana and the parasitoid Trichogramma evanescens. Parasitoid performance in host eggs of different sizes and originating from five grape cultivars was determined. Overall, egg parasitism was higher on cultivars on which L. botrana laid larg…
Microsporidian disease of the invasive amphipod Dikerogammarus villosus and the potential for its transfer to local invertebrate fauna.
2012
12 pages; International audience; Invasive species may introduce novel pathogens to a colonised area. Most of the time emerging pathogens are detected a posteriori, but recognition of a priori emergence of an invasive disease by host shift may be useful for predictive purposes. Here, we studied if the microsporidian parasite Cucumispora dikerogammari infecting the invasive Ponto-Caspian amphipod Dikerogammarus villosus, has the potential to become an emergent disease in invaded rivers in Western and Central Europe. We first showed that this parasite decreases the survival of D. villosus in the later stages of infection development. However, the host reproduces earlier in response to the inf…
Contrôle des ravageurs de cultures par les ennemis naturels : la plante hôte facteur régulateur du système immunitaire des chenilles de vers de la gr…
2013
10 pages; National audience; En raison des nombreux dégâts occasionnés par les vers de la grappe dans les vignobles, trouver un moyen de lutte efficace est devenu un réel challenge. A l’heure actuelle, la lutte biologique apparaît comme une alternative possible à la lutte chimique. Cependant, les résultats obtenus suite aux lâchers de parasitoïdes sont extrêmement variables dans leur efficacité. Des études approfondies de la biologie des vers de la grappe et de leurs parasitoïdes sont donc nécessaires afin d’affiner les méthodes de lutte biologique. Le système immunitaire des insectes représente la dernière ligne de défense des phytophages contre les parasitoïdes. Dans cette étude nous mett…
Immunoécologie des vertébrés et invertébrés : recherche sur la variabilité naturelle de la résistance parasitaire.
2007
1 page; National audience
Multidimensionality in host manipulation mimicked by serotonin injection.
2014
Manipulative parasites often alter the phenotype of their hosts along multiple dimensions. ‘Multidimensionality’ in host manipulation could consist in the simultaneous alteration of several physiological pathways independently of one another, or proceed from the disruption of some key physiological parameter, followed by a cascade of effects. We compared multidimensionality in ‘host manipulation’ between two closely related amphipods, Gammarus fossarum and Gammarus pulex, naturally and experimentally infected with Pomphorhynchus laevis (Acanthocephala), respectively. To that end, we calculated in each host–parasite association the effect size of the difference between infected and uninfect…
Larval size in acanthocephalan parasites : Influence of intraspecific competition and effects on intermediate host behavioural changes
2012
Abstract Background Parasites often face a trade-off between exploitation of host resources and transmission probabilities to the next host. In helminths, larval growth, a major component of adult parasite fitness, is linked to exploitation of intermediate host resources and is influenced by the presence of co-infecting conspecifics. In manipulative parasites, larval growth strategy could also interact with their ability to alter intermediate host phenotype and influence parasite transmission. Methods We used experimental infections of Gammarus pulex by Pomphorhynchus laevis (Acanthocephala), to investigate larval size effects on host behavioural manipulation among different parasite sibshi…
La monogamie humaine est-elle « naturelle » ?
2009
9 pages
Straightforward access to water-soluble unsymmetrical sulfoxanthene dyes: application to the preparation of far-red fluorescent dyes with large stoke…
2014
An efficient synthesis of water-soluble unsymmetrical sulforhodamine/sulforhodol fluorophores containing a single julolidine fragment is presented. Owing to their valuable spectral properties in aqueous buffers, these dyes, especially those bearing a free aniline or phenol moiety, are valuable components of fluorogenic probes for a variety of biosensing applications. A further extension of this synthetic methodology to unusual phenols, namely 7-N,N-dialkylamino-4-hydroxy coumarins has enabled us to provide a new family water-soluble dyes of large Stokes’ shift with far-red spectral features.
Evolutionary histories of symbioses between microsporidia and their amphipod hosts : contribution of studying two hosts over their geographic ranges.
2019
Title: Evolutionary histories of symbioses between microsporidia and their amphipod hosts : contribution of studying two hosts over their geographic ranges.Keywords: Symbioses, Phylogeny, Phylogeography, Amphipods, Host-Parasite, MicrosporidiaAbstract: Microsporidia are obligate endoparasites, exploiting their hosts with either vertical or horizontal transmission. While the former may promote co-speciation and host-specificity, the latter may promote shifts between host species. Freshwater amphipods are hosts for many microsporidian species, but no general pattern of host specificity and co-diversification is known.In my PhD work microsporidian infections, identified with SSU rDNA, were ass…