A glial amino-acid transporter controls synapse strength and courtship in Drosophila

Mate choice is an evolutionarily critical decision that requires the detection of multiple sex-specific signals followed by central integration of these signals to direct appropriate behavior. The mechanisms controlling mate choice remain poorly understood. Here, we show that the glial amino-acid transporter genderblind controls whether Drosophila melanogaster males will attempt to mate with other males. Genderblind (gb) mutant males showed no alteration in heterosexual courtship or copulation, but were attracted to normally unappealing male species-specific chemosensory cues. As a result, genderblind mutant males courted and attempted to copulate with other Drosophila males. This homosexual behavior could be induced within hours using inducible RNAi, suggesting that genderblind controls nervous system function rather than its development. Consistent with this, and indicating that glial genderblind regulates ambient extracellular glutamate to suppress glutamatergic synapse strength in vivo, homosexual behavior could be turned on and off by altering glutamatergic transmission pharmacologically and/or genetically

Acides aminés : système nerveux olfactif et alimentation

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Use of two odorants to control bactrocera oleae and ceratitis capitata

International audienceMany 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 infestation of fruits by limiting egg laying and population propagation. These compounds are non-toxic and could be used to control insects' threats while respecting the environment

The smell of love in Drosophila.

PMCID: PMC3617446 ; http://www.frontiersin.org/International audienceOdors are key sensory signals for social communication and food search in animals including insects. Drosophila melanogaster, is a powerful neurogenetic model commonly used to reveal molecular and cellular mechanisms involved in odorant detection. Males use olfaction together with other sensory modalities to find their mates. Here, we review known olfactory signals, their related olfactory receptors, and the corresponding neuronal architecture impacting courtship. OR67d receptor detects 11-cis-Vaccenyl Acetate (cVA), a male specific pheromone transferred to the female during copulation. Transferred cVA is able to reduce female attractiveness for other males after mating, and is also suspected to decrease male-male courtship. cVA can also serve as an aggregation signal, maybe through another OR. OR47b was shown to be activated by fly odors, and to enhance courtship depending on taste pheromones. IR84a detects phenylacetic acid (PAA) and phenylacetaldehyde (PA). These two odors are not pheromones produced by flies, but are present in various fly food sources. PAA enhances male courtship, acting as a food aphrodisiac. Drosophila males have thus developed complementary olfactory strategies to help them to select their mates

Biocontrol of drosophila suzukii by two fatty acids

International audienceOlfaction 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 increasing concentrations, and even to induce a reversible anesthesia. These 2 acids are non-toxic, and could be used to limit the spread and damages caused by Drosophila suzukii. Their use offers a solution to protect berry crops and cherries in an environmental-friendly manner by providing a non-killing technology suitable to preserve biodiversity. Patent N° EP19306102

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 trouve notamment une application dans le domaine agricole, vétérinaire, phytosanitaire

Une recherche bourguignonne au secours des maraîchers

Publication des interviews dans un journal hebdomadaire par Nadège HUBERT.National audienceDes chercheurs du CSGA ont découvert une alternative aux insecticides et sont aujourd'hui accompagnés par la Satt Sayens pour la transmettre au monde économique

Accelerated bang recovery in Drosophila genderblind mutants

Cystine-glutamate transporters import cystine into cells for glutathione synthesis and protection from oxidative stress, but also export significant amounts of glutamate. Increasing evidence suggests that ‘ambient extracellular glutamate’ secreted by cystine-glutamate transporters in the nervous system modulates glutamatergic synapse strength and behavior. To date, the only cystine-glutamate transporter mutants examined behaviorally are Drosophila genderblind mutants. These animals contain loss-of-function mutations in the ‘genderblind’ gene, which encodes an xCT subunit essential for cystine-glutamate transporter function. Genderblind was named based on a mutant courtship phenotype: male genderblind mutants are attracted to normally aversive male pheromones and thus court and attempt to copulate with both male and female partners equally. However, genderblind protein is expressed in many parts of the fly brain and thus might be expected to also regulate other behaviors, including behaviors not related to male courtship or chemosensation. Here, we show that genderblind mutants display faster recovery and increased negative geotaxis after strong mechanical stimuli (e.g., they climb faster and farther after vial banging). This phenotype is displayed by both males and females, consistent with strong genderblind expression in both sexes

JhI-21 plays a role in Drosophila insulin-like peptide release from larval IPCs via leucine transport

Abstract Insulin is present all across the animal kingdom. Its proper release after feeding is of extraordinary importance for nutrient uptake, regulation of metabolism, and growth. We used Drosophila melanogaster to shed light on the processes linking dietary leucine intake to insulin secretion. The Drosophila genome encodes 8 insulin-like peptides (“Dilps”). Of these, Dilp2 is secreted after the ingestion of a leucine-containing diet. We previously demonstrated that Minidiscs, related to mammalian system-L transporters, acts as a leucine sensor within the Dilp2-secreting insulin-producing cells (“IPCs”) of the brain. Here, we show that a second leucine transporter, JhI-21, of the same family is additionally necessary for proper leucine sensing in the IPCs. Using calcium imaging and ex-vivo cultured brains we show that knockdown of JhI-21 in IPCs causes malfunction of these cells: they are no longer able to sense dietary leucine or to release Dilp2 in a leucine dependent manner. JhI-21 knockdown in IPCs further causes systemic metabolic defects including defective sugar uptake and altered growth. Finally, we showed that JhI-21 and Minidiscs have no cumulative effect on Dilp2 release. Since system-L transporters are expressed by mammalian β-cells our results could help to better understand the role of these proteins in insulin signaling

Sex-specific anesthesia via olfactory receptor inhibition in Drosophila

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