Search results for "larva"
showing 10 items of 632 documents
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…
serrano gene and NaCl perception
2010
Gustatory information is considered to be important for animals to control behavior when they seek for food or partners. 60 members of gustatory receptor (Gr) genes have been identified in Drosophila.. However little is now about mechanisms of taste perception and transduction in response to stimuli. In order to identify new genes involved in gustation, we performed a genetic screen using Gal4-UAS system based on expression of the reporter gene in chemosensory organs and gustatory defects in larvae and adults. We identified the serrano (sano) gene, which encodes a 778 aa protein with a leucine zipper domain, a putative transmembrane domain, and putative bipartite nuclear localization signal…
Réponses comportementales et préférences envers les acides gras à longue chaîne chez Drosophila melanogaster
2011
Fatty-acids (FAs) are crucial for animal survival and reproduction since these molecules are involved in many metabolic pathways and constitute a substantial store of energy. Despite the strong relationship established between excessive FA consumption and severe human etiologies (obesity, cancer, vascular diseases), our knowledge of the mechanisms underlying FA perception and preference is limited particularly in invertebrates. This is one of the reasons why we decided to investigate, during our PhD thesis, the perception of long-chain FAs (C14:0, C16:0, C18:0, C18:1, C18:2, C18:3), using the model species Drosophila melanogaster. We have also attempted to characterize some of the biologica…
Grape cultivar affects larval and female fitness of the European grapevine moth, Lobesia botrana (Lepidoptera: Tortricidae)
2005
8 pages; International audience
Optimum and Maximum Host Sizes at Parasitism for the Endoparasitoid <I>Hyposoter didymator</I> (Hymenoptera: Ichneumonidae) Differ Greatl…
2007
Host size is considered a reliable indicator of host quality and an important determinant of parasitoid fitness. Koinobiont parasitoids attack hosts that continue feeding and growing during parasitism. In contrast with hemolymph-feeding koinobionts, tissue-feeding koinobionts face not only a minimum host size for successful development but also a maximum host size, because consumption of the entire host is often necessary for successful egression. Here we study interactions between a generalist tissue-feeding larval endoparasitoid, Hyposoter didymator Thunberg (Hymenoptera: Ichneumonidae) and two of its natural hosts, Spodoptera exigua Hübner and Chrysodeixis chalcites Esper (Lepidoptera: N…
Larval zebrafish as an in vitro model for evaluating toxicological effects of mycotoxins.
2020
The presence of mycotoxins in food has created concern. Mycotoxin prevalence in our environment has changed in the last few years maybe due to climatic and other environmental changes. Evidence has emerged from in vitro and in vivo models: some mycotoxins have been found to be potentially carcinogenic, embryogenically harmful, teratogenic, and to generate nephrotoxicity. The risk assessment of exposures to mycotoxins at early life stages became mandatory. In this regard, the effects of toxic compounds on zebrafish have been widely studied, and more recently, mycotoxins have been tested with respect to their effects on developmental and teratogenic effects in this model system, which offers …
Study of locomotion response and development in zebrafish (Danio rerio) embryos and larvae exposed to enniatin A, enniatin B, and beauvericin.
2021
Mycotoxins are secondary metabolites produced by a variety of fungi that contaminate food and feed resources, and are capable of inducing a wide range of toxicity. Here, we studied the developmental and behavioral toxicity in zebrafish (Danio rerio) embryos and larvae exposed to three mycotoxins: beauvericin (BEA), Enniatin A (ENN A), and Ennitain B (ENN B). Zebrafish embryos were collected after fertilization, treated individually from 1 to 6 dpf with BEA at 8, 16, 32 and, 64 μM and for both enniatins at 3.12, 6.25, 12.5 and, 25 μM. Mixture of mycotoxins were assayed as follows: i) for BEA + ENN A and BEA + ENN B at [32 + 12.5] μM and [16 + 6.25] μM; ii) for ENN A + ENN B at [12.5 + 12.5] …
Bioconcentration and metabolism of 3,4-dichloroaniline in different life stages of guppy and zebrafish
1993
Abstract Bioconcentration factors (BCF) and metabolism of 3,4-dichloroaniline in different life stages of guppy (Poecilia reticulata Peters ) and zebrafish (Brachydanio rerio Hamilton-Buchanan ) were investigated. The results prove that embryos of zebrafish, four-day-old yolk sac larvae, 17-day-old larvae and adult zebrafish are able to transform the chemical to 3,4-dichloroacetanilide. Bioconcentration factors in these life stages are between 30 and 42, exept yolk sac larvae showing a BCF of 86. 3,4-Dichloroacetanilide was also detected in extracts of newborn and adult guppies, but they are able to form an additional, yet unknown metabolite. The BCF varies from 34 in six-month-old guppies …
Study of the aminopeptidase N gene family in the lepidopterans Ostrinia nubilalis (Hübner) and Bombyx mori (L.): Sequences, mapping and expression
2010
Aminopeptidases N (APNs) are a class of ectoenzymes present in lepidopteran larvae midguts, involved in the Bacillus thuringiensis (Bt) toxins mode of action. In the present work, seven aminopeptidases have been cloned from the midgut of Ostrinia nubilalis, the major Lepidopteran corn pest in the temperate climates. Six sequences were identified as APNs because of the presence of the HEXXH(X)18E and GAMEN motifs, as well as the signal peptide and the GPI-anchor sequences. The remaining sequence did not contain the two cellular targeting signals, indicating it belonged to the puromycin-sensitive aminopeptidase (PSA) family. An in silico analysis allowed us to find orthologous sequences in Bo…
Development of the wing discs of Zophobas atratus under natural and experimental conditions: occurrence of a gradual larval-pupal commitment in the e…
1999
Using light and electron microscopy, we studied the development of the wing discs in the large beetle Zophobas atratus, under natural and experimental conditions. A reversible differentiation of the wing discs is usually observed during supernumerary instars of crowded larvae. Juvenile hormone analog (JHA) application during the wandering period or compelled experimental crowding during the larval-pupal switchover – or commitment – inhibits the onset of metamorphosis. Isolation, followed by recrowding, also induces the disc cells to secrete unusual cuticular material. Recrowding is able to trigger the reversal of metamorphosis during the 4-day period when larval-pupal commitment is taking p…