7-ketocholesterol and 7β-hydroxycholesterol: in vitro and animal models used to characterize their activities and to identify molecules preventing their toxicity

International audience; Oxysterols are molecules derived by the oxidation of cholesterol and can be formed either by auto-oxidation, enzymatically or by both processes. Among the oxysterols formed by auto-oxidation, 7-ketocholesterol and 7beta-hydroxycholesterol are the main forms generated. These oxysterols, formed endogenously and brought in large quantities by certain foods, have major cytotoxic properties. They are powerful inducers of oxidative stress, inducing dysfunction of organelles (mitochondria, lysosomes and peroxisomes) that can cause cell death. These molecules are often identified in increased amounts in common pathological states such as cardiovascular diseases, certain eye …

Use of two odorants to control bactrocera oleae and ceratitis capitata

International audience; Many insects are considered as pests because of the damage they cause to cultures. Growers and our society are waiting for environmentally safe strategies to prevent insect damages, without arming the environment and the biodiversity. Recently we discovered an innovative solution using some odorant molecules to control Drosophila suzukii behavior. Using this knowledge we started to investigate the possibility to apply this strategy to Bactrocera oleae (olive fruit fly) and Ceratitis capitata (Mediterranean fruit fly) to modify their social behavior. This new technology, which is protected by the patent n° EP19306102, could be particularly interesting to avoid infesta…

Human R1441C LRRK2 regulates the synaptic vesicle proteome and phosphoproteome in a Drosophila model of Parkinson's disease

International audience; Mutations in leucine-rich repeat kinase 2 (LRRK2) cause late-onset, autosomal dominant familial Parkinsons disease (PD) and variation at the LRRK2 locus contributes to the risk for idiopathic PD. LRRK2 can function as a protein kinase and mutations lead to increased kinase activity. To elucidate the pathophysiological mechanism of the R1441C mutation in the GTPase domain of LRRK2, we expressed human wild-type or R1441C LRRK2 in dopaminergic neurons of Drosophila and observe reduced locomotor activity, impaired survival and an age-dependent degeneration of dopaminergic neurons thereby creating a new PD-like model. To explore the function of LRRK2 variants in vivo, we …

Testing <em>Drosophila</em> Olfaction with a Y-maze Assay

Detecting signals from the environment is essential for animals to ensure their survival. To this aim, they use environmental cues such as vision, mechanoreception, hearing, and chemoperception through taste, via direct contact or through olfaction, which represents the response to a volatile molecule acting at longer range. Volatile chemical molecules are very important signals for most animals in the detection of danger, a source of food, or to communicate between individuals. Drosophila melanogaster is one of the most common biological models for scientists to explore the cellular and molecular basis of olfaction. In order to highlight olfactory abilities of this small insect, we describ…

Direct Sensing of Nutrients via a LAT1-like Transporter in Drosophila Insulin-Producing Cells

Summary Dietary leucine has been suspected to play an important role in insulin release, a hormone that controls satiety and metabolism. The mechanism by which insulin-producing cells (IPCs) sense leucine and regulate insulin secretion is still poorly understood. In Drosophila, insulin-like peptides (DILP2 and DILP5) are produced by brain IPCs and are released in the hemolymph after leucine ingestion. Using Ca2+-imaging and ex vivo cultured larval brains, we demonstrate that IPCs can directly sense extracellular leucine levels via minidiscs (MND), a leucine transporter. MND knockdown in IPCs abolished leucine-dependent changes, including loss of DILP2 and DILP5 in IPC bodies, consistent wit…

Acides aminés : système nerveux olfactif et alimentation

International audience

Fatty Acid Smell, Anesthesia, and Use on Fruit Crops

Odors convey important information to select a sex partner, to find a food source, or to detect a danger. Among those some volatile molecules have been shown to cause a reversible anesthesia. However, their mode of action appears still largely mysterious. Here we describe a novel property of Olfactory Receptor 47b (OR47b), on olfactory sensory neurons (OSNs) expressing male-specific transcription factor FruM. We found some interesting properties of a fatty acid that can be present on food sources and oviposition sites for Drosophilid species. We show that OR47b neurons projecting to VA1v glomerulus are sensitive to this odor, and that this influences Drosophila behavior causing a strong ave…

Spatio-temporal expression of Prospero is finely tuned to allow the correct development and function of the nervous system in Drosophila melanogaster.

0012-1606 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; Adaptive animal behaviors depend upon the precise development of the nervous system that underlies them. In Drosophila melanogaster, the pan-neural prospero gene (pros), is involved in various aspects of neurogenesis including cell cycle control, axonal outgrowth, neuronal and glial cell differentiation. As these results have been generally obtained with null pros mutants inducing embryonic lethality, the role of pros during later development remains poorly known. Using several pros-Voila (prosV) alleles, that induce multiple developmental and behavioral anomalies in the larva and in adult, we explored the…

The Amino Acid Transporter JhI-21 Coevolves with Glutamate Receptors, Impacts NMJ Physiology, and Influences Locomotor Activity in Drosophila Larvae

AbstractChanges in synaptic physiology underlie neuronal network plasticity and behavioral phenomena, which are adjusted during development. The Drosophila larval glutamatergic neuromuscular junction (NMJ) represents a powerful synaptic model to investigate factors impacting these processes. Amino acids such as glutamate have been shown to regulate Drosophila NMJ physiology by modulating the clustering of postsynaptic glutamate receptors and thereby regulating the strength of signal transmission from the motor neuron to the muscle cell. To identify amino acid transporters impacting glutmatergic signal transmission, we used Evolutionary Rate Covariation (ERC), a recently developed bioinforma…

7-Ketocholesterol effects on survival and growth in Drosophila melanogaster

International audience

Mild mutations in the pan neural gene prospero affect male-specific behaviour in Drosophila melanogaster

0376-6357 (Print) Journal Article Research Support, Non-U.S. Gov't; The fruitfly Drosophila melanogaster is one of the most appropriate model organisms to study the genetics of behaviour. Here, we focus on prospero (pros), a key gene for the development of the nervous system which specifies multiple aspects from the early formation of the embryonic central nervous system to the formation of larval and adult sensory organs. We studied the effects on locomotion, courtship and mating behaviour of three mild pros mutations. These newly isolated pros mutations were induced after the incomplete excision of a transposable genomic element that, before excision, caused a lethal phenotype during larv…

Sex-specific anesthesia via olfactory receptor inhibition in Drosophila

International audience

La recherche publique en France en 2019 : Diagnostic et propositions du Comité national

Projet porté par le Comité National du CNRS.; Dans le contexte de la préparation d’une loi de programmation pluriannuelle de la recherche, ce document présente la contribution du Comité national de la recherche scientifique à l’analyse de la situation de la recherche publique en France, de son évolution récente (depuis la loi LRU de 2008) et de ses perspectives, ainsi qu’un ensemble de propositions qui ont été finalisées et ont fait l’objet d’une approbation solennelle lors de la session plénière du Comité national organisée à Paris le 4 juillet 2019.

Role of MINIDISCS, a SLC7A amino-acid transporter, on glutamatergic activity in Drosophila melanogaster mushroom bodies.

Exploration of CYP27A1 function in eye cholesterol signaling between glia and neurons in Drosophila.

Biocontrol of drosophila suzukii by two fatty acids

International audience; Olfaction is a crucial sense for insects to detect food, seek partners or escape dangers. Volatile molecules are mainly perceived through insects' antenna. Odors bind to specific olfactory receptors located in sensilla. Olfactory sensory neurons then synapse on corresponding specific glomeruli of the antennal lobe, the primary olfaction center. This olfactory information is processed in higher centers to trigger a behavioral response. Understanding how odors can influence insect behavior is fundamental in order to protect cultures from pests. In this work, 2 volatile fatty acids are shown to modify significantly Drosophila suzukii courtship and copulation at increasi…

Composition répulsive et utilisations

La présente invention se rapporte à l'utilisation d’au moins un acide gras, avantageusement volatile et odorant, choisi dans le groupe 5 comprenant l’acide propionique, l’acide butyrique et/ou un dérivé de ceux-ci comme principe actif répulsif et/ou pour contrôler la reproduction de brachycères, et à l’utilisation d’une composition, en particulier phytosanitaire, comprenant au moins un acide gras, avantageusement volatile et odorant, choisi dans le groupe comprenant l’acide propionique, 10 l’acide butyrique et/ou un dérivé de ceux-ci comme principe actif répulsif et/ou pour contrôler la reproduction de brachycères avantageusement par olfaction, et non-insecticide. La présente invention trou…

Prospero mutants induce precocious sexual behavior in Drosophila males.

0001-8244 (Print) Journal Article Research Support, Non-U.S. Gov't; Brain maturation, a developmental process influenced by both endogenous and environmental factors, can affect sexual behavior. In vertebrates and invertebrates, sexual maturation is under the influence of hormones and neuromodulators, but the role of developmental genes in this process is still poorly understood. We report that prospero (pros), a gene crucial for nervous system development, can change the age of onset of sexual behavior in Drosophila melanogaster males: adult males carrying a single copy of several pros mutations court females and mate at a younger age than control males. However, these pros mutations had n…