24 research outputs found
Exploratory behaviour in NO-dependent cyclase mutants of Drosophila shows defects in coincident neuronal signalling
<p>Abstract</p> <p>Background</p> <p><it>Drosophila </it>flies explore the environment very efficiently in order to colonize it. They explore collectively, not individually, so that when a few land on a food spot, they attract the others by signs. This behaviour leads to aggregation of individuals and optimizes the screening of mates and egg-laying on the most favourable food spots.</p> <p>Results</p> <p>Flies perform cycles of exploration/aggregation depending on the resources of the environment. This behavioural ecology constitutes an excellent model for analyzing simultaneous processing of neurosensory information. We reasoned that the decision of flies to land somewhere in order to achieve aggregation is based on simultaneous integration of signals (visual, olfactory, acoustic) during their flight. On the basis of what flies do in nature, we designed laboratory tests to analyze the phenomenon of neuronal coincidence. We screened many mutants of genes involved in neuronal metabolism and the synaptic machinery.</p> <p>Conclusion</p> <p>Mutants of NO-dependent cyclase show a specifically-marked behaviour phenotype, but on the other hand they are associated with moderate biochemical defects. We show that these mutants present errors in integrative and/or coincident processing of signals, which are not reducible to the functions of the peripheral sensory cells.</p
Continued Neurogenesis in Adult Drosophila as a Mechanism for Recruiting Environmental Cue-Dependent Variants
Background The skills used by winged insects to explore their environment are strongly dependent upon the integration of neurosensory information comprising visual, acoustic and olfactory signals. The neuronal architecture of the wing contains a vast array of different sensors which might convey information to the brain in order to guide the trajectories during flight. In Drosophila, the wing sensory cells are either chemoreceptors or mechanoreceptors and some of these sensors have as yet unknown functions. The axons of these two functionally distinct types of neurons are entangled, generating a single nerve. This simple and accessible coincidental signaling circuitry in Drosophila constitutes an excellent model system to investigate the developmental variability in relation to natural behavioral polymorphisms. Methodology/Principal Findings A fluorescent marker was generated in neurons at all stages of the Drosophila life cycle using a highly efficient and controlled genetic recombination system that can be induced in dividing precursor cells (MARCM system, flybase web site). It allows fluorescent signals in axons only when the neuroblasts and/or neuronal cell precursors like SOP (sensory organ precursors) undergo division during the precedent steps. We first show that a robust neurogenesis continues in the wing after the adults emerge from the pupae followed by an extensive axonal growth. Arguments are presented to suggest that this wing neurogenesis in the newborn adult flies was influenced by genetic determinants such as the frequency dependent for gene and by environmental cues such as population density. Conclusions We demonstrate that the neuronal architecture in the adult Drosophila wing is unfinished when the flies emerge from their pupae. This unexpected developmental step might be crucial for generating non-heritable variants and phenotypic plasticity. This might therefore constitute an advantage in an unstable ecological system and explain much regarding the ability of Drosophila to robustly adapt to their environment
Structure du genome de l'abeille Apis mellifera : analyse des sequences hautement et moyennement repetees
*INRA Centre d'Antibes Diffusion du document : INRA Centre d'Antibes DiplĂ´me : Dr. d'Universit
Cloning and expression of cytochrome P450 genes belonging to the CYP4 family and to a novel family, CYP48, in two Hymenopteran insects, Trichogramma cacoeciae and Apis melifera
International audienc
Caracterisation d'une famille de sequences d'ADN Alu I hautement repetees et conservees de facon inhabituelle chez l'abeille
International audienc
Genetic improvment of Trichogramma to pesticide resistance
International audienc
Amélioration génétique du trichogramme par transgenèse pour l'obtention d'individus résistants aux pesticides
National audienc
Cloning and characterization of a highly conserved satellite DNA sequence specific for the phytoparasitic nematode Bursaphelenchus xylophilus
International audienc
Identification of pinewood nematode geographic isolates (Bursaphelenchus spp.) using homologous DNA probes
International audienc