Perception périphérique des signaux sensoriels. 1- Gustation

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Is mate choice in Drosophila males guided by olfactory or gustatory pheromones ?

International audience; Drosophila melanogaster flies use both olfactory and taste systems to detect sex pheromones and select the most suitable mate for reproduction. In nature, flies often face multiple potential partners and should have an acute sensory ability to discriminate between different pheromonal bouquets. We investigated both the pheromones and the chemosensory neurons influencing Drosophila mate choice. We measured various courtship traits in single tester males simultaneously presented with two target male and/or female flies carrying different pheromonal bouquets (pairs of control flies of the same or different sex, same-sex target pairs of pheromonal variant strains). The c…

Transcriptional Control of Quality Differences in the Lipid-Based Cuticle Barrier in Drosophila suzukii and Drosophila melanogaster

Cuticle barrier efficiency in insects depends largely on cuticular lipids. To learn about the evolution of cuticle barrier function, we compared the basic properties of the cuticle inward and outward barrier function in adults of the fruit flies Drosophila suzukii and Drosophila melanogaster that live on fruits sharing a similar habitat. At low air humidity, D. suzukii flies desiccate faster than D. melanogaster flies. We observed a general trend indicating that in this respect males are less robust than females in both species. Xenobiotics penetration occurs at lower temperatures in D. suzukii than in D. melanogaster. Likewise, D. suzukii flies are more susceptible to contact insecticides …

Genetic identification of neurons controlling a sexually dimorphic behaviour

0960-9822 (Print) Journal Article Research Support, Non-U.S. Gov't; In the fruit fly Drosophila melanogaster, locomotor activity is sexually dimorphic: female flies constantly modulate their activity pattern whereas males show a steadier, stereotyped walking pace [1]. Here, we mapped the area of the brain controlling this behavioural dimorphism. Adult male Drosophila expressing a dominant feminising transgene in a small cluster of neurons in the pars intercerebralis exhibited a female-like pattern of locomotor activity. Genetic ablation of these neurons prevented the feminisation of the locomotor activity of transgenic males. The results suggest that this cluster of neurons modulates sex-sp…

Genetic study of the production of sexually dimorphic cuticular hydrocarbons in relation with the sex-determination gene transformer in Drosophila melanogaster

In Drosophila melanogaster, the main cuticular hydrocarbons (HCs) are some of the pheromones involved in mate discrimination. These are sexually dimorphic in both their occurrence and their effects. The production of predominant HCs has been measured in male and female progeny of 220 PGal4 lines mated with the feminising UAS-transformer transgenic strain. In 45 lines, XY flies were substantially or totally feminised for their HCs. Surprisingly, XX flies of 14 strains were partially masculinised. Several of the PGal4 enhancer-trap variants screened here seem to interact with sex determination mechanisms involved in the control of sexually dimorphic characters. We also found a good relationsh…

Voila, a New Drosophila Courtship Variant that Affects the Nervous System: Behavioral, Neural, and Genetic Characterization

InDrosophila melanogaster, a specificPGAL4transposon induces theVoila1genetic variant and produces multiple phenotypes. HomozygousVoila1/1flies rarely reach adulthood, whereas heterozygousVoila1/+adult males show strong bisexual behavior. Males with a single copy ofVoila1driving the feminizing transgeneUAS-transformershow very reduced sexual activity but no overall effect on their behavior.Voila1is specifically expressed in the nervous system. In the CNS, it is expressed mainly in the mushroom bodies and, to a lesser extent, in the antennal lobes. In the peripheral nervous system, GAL4 expression is almost entirely restricted to the gustatory sensilla. Using chromosomal deficiencies, the be…

Fatty-acid preference changes during development in Drosophila melanogaster.

WOS:000296521400044; International audience; Fatty-acids (FAs) are required in the diet of many animals throughout their life. However, the mechanisms involved in the perception of and preferences for dietary saturated and unsaturated FAs (SFAs and UFAs, respectively) remain poorly explored, especially in insects. Using the model species Drosophila melanogaster, we measured the responses of wild-type larvae and adults to pure SFAs (14, 16, and 18 carbons) and UFAs (C18 with 1, 2, or 3 double-bonds). Individual and group behavioral tests revealed different preferences in larvae and adults. Larvae preferred UFAs whereas SFAs tended to induce both a strong aversion and a persistent aggregation…

Drosophila female courtship and mating behaviors: sensory signals, genes, neural structures and evolution.

International audience; Interest in Drosophila courtship behavior has a long-standing tradition, starting with the works by Sturtevant in 1915, and by Bastock and Manning in the 50s. The neural and genetic base of Drosophila melanogaster courtship behavior has made big strides in recent years, but the studies on males far outnumber those on females. Recent technical developments have made it possible to begin to unravel the biological substrates underlying the complexity of Drosophila female sexual behavior and its decisive effect on mating success. The present review focus more on the female side and summarizes the sensory signals that the male sends, using multiple channels, and which neu…

"Comprendre la vie"

Ma thèse en 180 secondes : la victoire de Karen Rihani

Courtship behaviour of Drosophila melanogaster revisited

0003-3472 doi: DOI: 10.1016/j.anbehav.2006.01.027; Nearly all studies of Drosophila melanogaster courtship have focused exclusively on male behaviour. Female precopulatory behaviour is often relegated to ‘accept' or ‘reject' mating, and how female behaviour interacts with that of males remains largely unknown. Using a video-computing approach, we measured 10 behavioural states and 22 elementary behaviours that occur during the precopulatory phase of Canton-S (Cs) flies. Male and female behaviours were studied under a variety of social conditions. This allowed us to identify which one(s) is relevant to courtship or to general activity. Our analysis showed that the courtship repertoire was no…

The role of Odorant-Binding Proteins in nutrition under the control of microbiota

Modulation of free-flight response in Drosophila

World-wide variation in Drosophila melanogaster sex pheromone: behavioural effects, genetic bases and potential evolutionary consequences

0016-6707 (Print) Journal Article Research Support, Non-U.S. Gov't; In Drosophila melanogaster, male wing vibration, a key element of courtship behaviour, is most efficiently induced by a female-specific contact pheromone cis, cis 7,11 heptacosadiene (7,11 HD), which is the main mature female cuticular hydrocarbon in the CS laboratory strain. A study of 63 strains from around the world revealed that flies from Sub-Saharan Africa and the Caribbean are unique in showing low levels 7,11 HD and high levels of the position isomer 5,9 HD. This difference maps to chromosome III, perhaps indicating a simple genetic control of the 7,11 HD:5,9 HD ratio. Females from strains with high levels of 7,11 H…

Courtship Behavior of Brain Mosaics in Drosophila

0167-7063 (Print) Journal Article Research Support, Non-U.S. Gov't; Sites in the brain that show functional, sexual dimorphism in courtship behavior have been mapped at high resolution in male/female mosaics of Drosophila melanogaster. The sex mosaics were produced by enhancer-trap expression of GAL4 driving the female-spliced form of the transformer gene (tra), revealing sites in the dorsal brain, lateral protocerebrum, suboesophageal, thoracic and abdominal ganglia, and suggesting the importance of cross-talk between these regions in the implementation of the courtship sequence.

INHIBITION OF FATTY ACID DESATURASES INDrosophila melanogasterLARVAE BLOCKS FEEDING AND DEVELOPMENTAL PROGRESSION

International audience; Fatty acid desaturases are metabolic setscrews. To study their systemic impact on growth in Drosophila melanogaster, we inhibited fatty acid desaturases using the inhibitor CAY10566. As expected, the amount of desaturated lipids is reduced in larvae fed with CAY10566. These animals cease feeding soon after hatching, and their growth is strongly attenuated. A starvation program is not launched, but the expression of distinct metabolic genes is activated, possibly to mobilize storage material. Without attaining the normal size, inhibitor-fed larvae molt to the next stage indicating that the steroid hormone ecdysone triggers molting correctly. Nevertheless, after moltin…

Cuticular hydrocarbons: their evolution and roles in Drosophila pheromonal communication

0001-8244 (Print) Journal Article Review; I review the recent literature on cuticular hydrocarbons (CHs) in Drosophila. First, the major structural features of CHs are examined in a variety of species with regard to phylogeny. The genetic bases of the CH variation between and within species have been investigated with some of the genes involved characterized and manipulated. The effect of non-genetic factors as temperature, food and development is also examined with regard to CH production. Using a model involving the stimulating or the inhibiting role of CHs, it is possible to speculate on the mechanisms of CH perception and on the role(s) that these substances could play on sexual isolati…

Pheromonal imprinting in Drosophila melanogaster: preadult exposure affects free flight odor tracking in adult

International audience

Desat expression in neural and non-neural tissues separately affects perception and emission of sex pheromones in Drosophila

Dysfunction of Oskyddad causes Harlequin-type ichthyosis-like defects in Drosophila melanogaster.

Prevention of desiccation is a constant challenge for terrestrial organisms. Land insects have an extracellular coat, the cuticle, that plays a major role in protection against exaggerated water loss. Here, we report that the ABC transporter Oskyddad (Osy)—a human ABCA12 paralog—contributes to the waterproof barrier function of the cuticle in the fruit fly Drosophila melanogaster. We show that the reduction or elimination of Osy function provokes rapid desiccation. Osy is also involved in defining the inward barrier against xenobiotics penetration. Consistently, the amounts of cuticular hydrocarbons that are involved in cuticle impermeability decrease markedly when Osy activity is reduced. …

The preference behavior of Drosophila to fatty acids changes during development

Plasticity of chemosensory-driven behavior in insects

The desaturase1 gene affects reproduction before, during and after copulation in Drosophila melanogaster

Desaturase1 (desat1) is one of the few genes known to be involved in the two complementary aspects of sensory communication — signal emission and signal reception — in Drosophila melanogaster. In p...

Gene Regulation and Species-Specific Evolution of Free Flight Odor Tracking in Drosophila

Running title: flight evolution in Drosophila This is an invited contribution to the special issue on Genetics of Adaptation based on a symposium of the same name at the National Centre for Biological Sciences (TIFR, Bangalore, India) in November 2016; International audience; The flying ability of insects has coevolved with the development of organs necessary to take-off from the ground, generate, and modulate lift during flight in complex environments. Flight orientation to the appropriate food source and mating partner depends on the perception and integration of multiple chemical signals. We used a wind tunnel-based assay to investigate the natural and molecular evolution of free flight …

Larval and pheromones modulate larval food choice in Drosophila

Symposium overview: Evolution of pheromonal communication in insects.

1749-6632 (Electronic) 0077-8923 (Linking) Journal Article Review

Function of odorant-binding proteins in the Drosophila melanogaster chemoreception

National audience; Function of odorant-binding proteins in the Drosophila [i]melanogaster[/i] chemoreception. 18. rencontre du Club de neurobiologie des invertébrés

Transient and Permanent Experience with Fatty Acids Changes Drosophila melanogaster Preference and Fitness

Food and host-preference relies on genetic adaptation and sensory experience. In vertebrates, experience with food-related cues during early development can change adult preference. This is also true in holometabolous insects, which undergo a drastic nervous system remodelling during their complete metamorphosis, but remains uncertain in Drosophila melanogaster. We have conditioned D. melanogaster with oleic (C18:1) and stearic (C18:0) acids, two common dietary fatty acids, respectively preferred by larvae and adult. Wild-type individuals exposed either during a transient period of development-from embryo to adult-or more permanently-during one to ten generation cycles-were affected by such…

Increased dopamine level enhances male-male courtship in Drosophila

1529-2401 (Electronic) Journal Article Research Support, Non-U.S. Gov't; Sexual behavior between males is observed in many species, but the biological factors involved are poorly known. In mammals, manipulation of dopamine has revealed the role of this neuromodulator on male sexual behavior. We used genetic and pharmacological approaches to manipulate the dopamine level in dopaminergic cells in Drosophila and investigated the consequence of this manipulation on male-male courtship behavior. Males with increased dopamine level showed enhanced propensity to court other males but did not change their courtship toward virgin females, general olfactory response, general gustatory response, or lo…

The role of cuticular pheromones in courtship conditioning of Drosophila males

1072-0502 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S.; Courtship conditioning is an associative learning paradigm in Drosophila melanogaster, wherein male courtship behavior is modified by experience with unreceptive, previously mated females. While the training experience with mated females involves multiple sensory and behavioral interactions, we hypothesized that female cuticular hydrocarbons function as a specific chemosensory conditioned stimulus in this learning paradigm. The effects of training with mated females were determined in courtship tests with either wild-type virgin females as courtship targets, or with…

Functional Gustatory Role of Chemoreceptors in Drosophila Wings

Summary: Neuroanatomical evidence argues for the presence of taste sensilla in Drosophila wings; however, the taste physiology of insect wings remains hypothetical, and a comprehensive link to mechanical functions, such as flight, wing flapping, and grooming, is lacking. Our data show that the sensilla of the Drosophila anterior wing margin respond to both sweet and bitter molecules through an increase in cytosolic Ca2+ levels. Conversely, genetically modified flies presenting a wing-specific reduction in chemosensory cells show severe defects in both wing taste signaling and the exploratory guidance associated with chemodetection. In Drosophila, the chemodetection machinery includes mechan…

Regulation of cuticular hydrocarbon profile maturation by Drosophila tanning hormone, bursicon, and its interaction with desaturase activity

International audience; Shortly after emergence the exoskeleton (cuticle) of adult insects is rapidly expanded, hardened (sclerotized), and pigmented (melanized). In parallel with this process, the oenocytes, which are large polyploid cells located below the abdominal epidermis, secrete onto the cuticle a cocktail of cuticular hydrocarbons (CHs) and waxes. These improve the waterproofing of the cuticle, and also provide important chemosensory and pheromonal cues linked with gender, age, and species differentiation. The hardening and pigmentation of the new cuticle are controlled by the neurohormone, bursicon, and its receptor, encoded by the DLGR2 receptor, rickets (rk); by contrast, little…

Behavioral and evolutionnary role of cuticular hydrocarbons in diptera

Cholinergic Control of Synchronized Seminal Emissions in Drosophila

0960-9822 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; In many animal species, copulation involves the coordinated release of both sperm and seminal fluid, including substances that change female fertility and postmating behavior. In Drosophila melanogaster, these substances increase female fertility and prevent mating with a second male. By using a PGal4 strain, we targeted together with other cells a dozen cholinergic neurons found only in the male abdominal ganglion (Abg-MAch). Genetic feminization apparently deleted these neurons in males and significantly increased their copulation duration, blocked their fertility in 60% of cases, and only weakly repress…

Eco-genetics of desiccation resistance in Drosophila.

International audience; Climate change globally perturbs water circulation thereby influencing ecosystems including cultivated land. Both harmful and beneficial species of insects are likely to be vulnerable to such changes in climate. As small animals with a disadvantageous surface area to body mass ratio, they face a risk of desiccation. A number of behavioural, physiological and genetic strategies are deployed to solve these problems during adaptation in various Drosophila species. Over 100 desiccation-related genes have been identified in laboratory and wild populations of the cosmopolitan fruit fly Drosophila melanogaster and its sister species in large-scale and single-gene approaches…

desat1 and the Evolution of Pheromonal Communication in Drosophila

1749-6632 (Electronic) 0077-8923; The evolution of communication is a fundamental biological problem. The genetic control of the signal and its reception must be tightly coadapted, especially in interindividual sexual communication. However, there is very little experimental evidence for tight genetic linkage connecting the emission of a signal and its reception. In Drosophila melanogaster, desat1 is the first known gene that simultaneously affects the emission and the perception of sex pheromones. Our experiments show that both aspects of pheromonal communication (the emission and the perception of sex pheromones) depend on distinct genetic control and may result from tissue-specific expre…

Extended Flight Bouts Require Disinhibition from GABAergic Mushroom Body Neurons

Summary Insect flight is a complex behavior that requires the integration of multiple sensory inputs with flight motor output. Although previous genetic studies identified central brain monoaminergic neurons that modulate Drosophila flight, neuro-modulatory circuits underlying sustained flight bouts remain unexplored. Certain classes of dopaminergic and octopaminergic neurons that project to the mushroom body, a higher integrating center in the insect brain, are known to modify neuronal output based on contextual cues and thereby organismal behavior. This study focuses on how monoaminergic modulation of mushroom body GABAergic output neurons (MBONs) regulates the duration of flight bouts. O…

The implication of OBP28a in Drosophila melanogaster chemosensory perception

National audience; Chemoperception is critical for animals to detect nutritive food and avoid toxic compounds. As many other insects, Drosophila melanogaster uses various semiochemicals including pheromones and food volatiles to identify a suitable ecological niche and a mating partner. Chemosensory detection is mostly mediated by olfactory and gustatory systems involving several multigene chemoreceptor families. Volatile and non-volatile chemicals compounds entering into the sensory organ (sensillum) must be solubilized before being transported through the hydrophilic sensillum lymph bathing the chemosensory neurons. Such perireceptor events involve a family of soluble proteins named odora…

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…

Effect of genes, social experience, and their interaction on the courtship behaviour of transgenic Drosophila males

Behaviour depends (a) on genes that specify the neural and non-neural elements involved in the perception of and responses to sensory stimuli and (b) on experience that can modulate the fine development of these elements. We exposed transgenic and control Drosophila melanogaster males, and their hybrids, to male siblings during adult development and measured the contribution of genes and of experience to their courtship behaviour. The transgene CheB42a specifically targets male gustatory sensillae and alters the perception of male inhibitory pheromones which leads to frequent male–male interactions. The age at which social experience occurred and the genotype of tester males induced a varia…

Dietary rescue of altered metabolism gene reveals unexpected [i]Drosophila[/i] mating cues

Running title: Dietary rescue of metabolic mutation and reproduction; To develop and reproduce, animals need long-chain Mono and PolyUnsaturated Fatty Acids (MUFAs; PUFAs). Although some UFAs can be synthesized by the organism, others must be provided by the diet. The gene desat1, involved in Drosophila melanogaster UFA metabolism, is necessary for both larval development and for adult sex pheromone communication. We first characterized desat1 expression in larval tissues. Then, we found that larvae in which desat1 expression was knocked down throughout development died during the larval stages when raised on standard food. By contrast pure MUFAs or PUFAs, but not saturated FAs, added to th…

Dysfunction of Torr causes a Harlequin-type ichthyosis-like phenotype in Drosophila melanogaster

AbstractPrevention of desiccation is a constant challenge for terrestrial organisms. Land insects have an extracellular coat, the cuticle, that plays a major role in protection against exaggerated water loss. Here, we report that the ABC transporter Torr - a human ABCA12 paralog - contributes to the waterproof barrier function of the cuticle in the fruit fly Drosophila melanogaster. We show that the reduction or elimination of Torr function provokes rapid desiccation. Torr is also involved in defining the inward barrier against xenobiotics penetration. Consistently, the amounts of cuticular hydrocarbons that are involved in cuticle impermeability decrease markedly when Torr activity is redu…

Experimental introgression to evaluate the impact of sex specific traits onDrosophila melanogasterincipient speciation

ABSTRACTSex specific traits are involved in speciation but it is difficult to determine whether their variation initiates or reinforces sexual isolation. In some insects, speciation depends of the rapid change of expression in desaturase genes coding for sex pheromones. Two closely related desaturase genes are involved inDrosophila melanogasterpheromonal communication:desat1affects both the production and the reception of sex pheromones whiledesat2is involved in their production in flies of Zimbabwe populations. There is a strong asymmetric sexual isolation between Zimbabwe populations and all other “Cosmopolitan” populations: Zimbabwe females rarely copulate with Cosmopolitan males whereas…

Cytochrome P450-dependent metabolism of caffeine in [i]Drosophila melanogaster[/i]

Caffeine (1, 3, 7-trimethylxanthine), an alkaloid produced by plants, has antioxidant and insecticide properties that can affect metabolism and cognition. In vertebrates, the metabolites derived from caffeine have been identified, and their functions have been characterized. However, the metabolites of caffeine in insects remain unknown. Thus, using radiolabelled caffeine, we have identified some of the primary caffeine metabolites produced in the body of Drosophila melanogaster males, including theobromine, paraxanthine and theophylline. In contrast to mammals, theobromine was the predominant metabolite (paraxanthine in humans; theophylline in monkeys; 1, 3, 7-trimethyluric acid in rodents…

Drosophila adult and larval pheromones modulate larval food choice

Insects use chemosensory cues to feed and mate. In Drosophila , the effect of pheromones has been extensively investigated in adults, but rarely in larvae. The colonization of natural food sources by Drosophila buzzatii and Drosophila simulans species may depend on species-specific chemical cues left in the food by larvae and adults. We identified such chemicals in both species and measured their influence on larval food preference and puparation behaviour. We also tested compounds that varied between these species: (i) two larval volatile compounds: hydroxy-3-butanone-2 and phenol (predominant in D. simulans and D. buzzatii , respectively), and (ii) adult cuticular hydrocarbons (CHs). Dro…

Identification and characterization of the first Drosophila larval pheromones

Two sexually dimorphic Odorant binding proteins are affected by microbiota

Identification and characterization of the first Drosophila larval pheromone

Reduction of Dopamine Level Enhances the Attractiveness of Male Drosophila to Other Males

1932-6203 (Electronic); Dopamine is an important neuromodulator in animals and its roles in mammalian sexual behavior are extensively studied. Drosophila as a useful model system is widely used in many fields of biological studies. It has been reported that dopamine reduction can affect female receptivity in Drosophila and leave male-female courtship behavior unaffected. Here, we used genetic and pharmacological approaches to decrease the dopamine level in dopaminergic cells in Drosophila, and investigated the consequence of this manipulation on male homosexual courtship behavior. We find that reduction of dopamine level can induce Drosophila male-male courtship behavior, and that this beha…

A Drosophila male pheromone affects female sexual receptivity.

Sex pheromones are chemical signals frequently required for mate choice, but their reciprocal role on mate preference has rarely been shown in both sexes. InDrosophila melanogasterflies, the predominant cuticular hydrocarbons (CHs) are sexually dimorphic: only females produce 7,11-dienes, whereas 7-tricosene (7-T) is the principal male CH. Males generally prefer females with 7,11-dienes, but the role of 7-T on female behaviour remains unclear. With perfumed males, control females mated faster and more often with males carrying increased levels of 7-T showing that this CH acts as a chemical stimulant forD. melanogasterfemales. Control females—but not antenna-less females—could detect small v…

Temperature affects the ontogeny of sexually dimorphic cuticular hydrocarbons inDrosophila melanogaster

0022-0949 (Print) Journal Article Research Support, Non-U.S. Gov't; Hydrocarbons on the cuticle of mature Drosophila melanogaster flies play a crucial role in mate recognition, and protect against dehydration. We measured the effect of temperature on mature cuticular hydrocarbons (CHs) by (i) rearing two control strains at different temperatures, (ii) shifting the temperature after metamorphosis and (iii) inducing a single heat-shock pulse in control and heat-sensitive transgenic strains, over a period of 3 days following adult eclosion. This study describes the time course of the events involved in the production of male- and female-predominant CHs. We also found that 'immature' CHs, sexua…

Three decades of pheromonal research in Drosophila: some answers and many questions

International audience; Over the last 30 years, pheromonal research in Drosophila has considerably expanded from the pioneering characterization of contact sex-pheromones in D. melanogaster adults1 right up to the recent discovery of the receptor proteins for these compounds.2,. The two sides of pheromonal communication – production and perception – have been explored using molecular, genetic, cellular, biochemical, physiological, ethological and evolutionary approaches3. Developmental and environmental effects on hydrocarbon production and the mechanisms underlying the plasticity of their perception have been also investigated3. Over the past few years, there has been a particular focus on…

The 40-Year Mystery of Insect Odorant-Binding Proteins

International audience; The survival of insects depends on their ability to detect molecules present in their environment. Odorant-binding proteins (OBPs) form a family of proteins involved in chemoreception. While OBPs were initially found in olfactory appendages, recently these proteins were discovered in other chemosensory and non-chemosensory organs. OBPs can bind, solubilize and transport hydrophobic stimuli to chemoreceptors across the aqueous sensilla lymph. In addition to this broadly accepted “transporter role”, OBPs can also buffer sudden changes in odorant levels and are involved in hygro-reception. The physiological roles of OBPs expressed in other body tissues, such as mouthpar…

Taste perception and behavior in rodents and flies

Taste, one of the five senses, plays a key role in food ingestion. The recent identification of molecular markers for taste cells (e.g., taste receptors and signaling components) has provided tools to investigate the functional organization of the gustatory system. This new information contributes to our understanding of taste-associated behaviors.

Courtship in Drosophila

0066-4197 (Print) Journal Article Review; Courtship is a complex behavior in Drosophila that recruits a wide range of genes for its realization, including those concerning sex determination, ion channels, and circadian rhythms. Results from different experimental approaches-behavioral and genetic comparisons between species, analysis of mutants and mosaics, and identification of specific sensory stimuli-sketch the outlines of a set of pleiotropic genes acting on a distributed system in the brain to produce the species-specific sequence of responses and actions.

Implication de l’OBP19b dans la perception gustative des acides aminés chez Drosophila melanogaster

National audience; La chimioperception est nécessaire à la détection des aliments nutritifs et à l’identification des composés toxiques, d’une niche écologique appropriée et des partenaires sexuels. Comme beaucoup d'autres insectes, la mouche du vinaigre, Drosophila melanogaster, possède des capacités chimiosensorielles performantes, la rendant très sensible en lui permettant de détecter et discriminer un large panel de substances chimiques. Chez la Drosophile, cette détection est réalisée par les systèmes chimiosensoriels gustatifs et olfactifs impliquant plusieurs familles de récepteurs. Les composés chimiques volatils et non volatils qui pénétrent les organes sensoriels (sensilles) doive…

Genetic elimination of known pheromones reveals the fundamental chemical bases of mating and isolation in Drosophila

Overexpression of the UAS-tra transgene in Drosophila melanogaster females led to the complete elimination of their cuticular pheromones. According to current models of Drosophila behavior, these flies should induce no courtship. In fact, they are still attractive to conspecific males. Three classes of stimuli are shown to induce courtship, with different effects on male behavior: ( i ) known pheromones produced by control females, ( ii ) stimuli produced by living control and transgenic flies, and ( iii ) as-yet-undetermined pheromones present on both control and transgenic flies. Only the latter class of pheromones are required for mating. They appear to represent a layer of ancestral at…

PGal4 excision reveals the pleiotropic effects of Voila, a Drosophila locus that affects development and courtship behaviour

0016-6723 (Print) Journal Article Research Support, Non-U.S. Gov't; In Drosophila melanogaster, the PGal4 transposon inserted at the chromosomal site 86E1-2 is associated with the Voila1 allele that causes multiple phenotypes. Homozygous Voila1/1 flies rarely reach adulthood and heterozygous Voila1/+ adult males display strong homosexual courtship behaviour. Both normal behavioural and developmental phenotypes were rescued by remobilizing the PGal4 element. Yet, the rescue of heterosexual courtship and of adult viability did not occur in the same strains, indicating that these defects have different genetic origins. Furthermore, many strains showed a partial rescue of both characters. Molec…

The consequences of regulation of desat1 expression for pheromone emission and detection in Drosophila melanogaster.

AbstractSensory communication depends on the precise matching between the emission and the perception of sex- and species-specific signals; understanding both the coevolutionary process and the genes involved in both production and detection is a major challenge. desat1 determines both aspects of communication—a mutation in desat1 simultaneously alters both sex pheromone emission and perception in Drosophila melanogaster flies. We investigated whether the alteration of pheromonal perception is a consequence of the altered production of pheromones or if the two phenotypes are independently controlled by the same locus. Using several genetic tools, we were able to separately manipulate the tw…

Genes involved in sex pheromone discrimination in Drosophila melanogaster and their background-dependent effect.

International audience; Mate choice is based on the comparison of the sensory quality of potential mating partners, and sex pheromones play an important role in this process. In Drosophila melanogaster, contact pheromones differ between male and female in their content and in their effects on male courtship, both inhibitory and stimulatory. To investigate the genetic basis of sex pheromone discrimination, we experimentally selected males showing either a higher or lower ability to discriminate sex pheromones over 20 generations. This experimental selection was carried out in parallel on two different genetic backgrounds: wild-type and desat1 mutant, in which parental males showed high and l…

Genes involved in sex pheromones discrimination and their context-dependent effect

Mate choice is based on the comparison of the sensory quality of potential mating partners and sex pheromones are important with regard to mate choice. In Drosophila melanogaster, male and female contact pheromones diverge both for their occurence and for their effects — respectively inhibitory and stimulatory — on male courtship. To investigate the genetic basis of sex pheromones discrimination in male flies, we experimentally selected, during 20 generations, lines in which males showed either the higher or the lower ability to discriminate sex pheromones. This experimental selection was carried out with wild-type and desat1 mutant genetic backgrounds in which parental males respectively s…

Chemically mediated sexual isolation between Zimbabwean endemic and cosmopolitan populations of Drosophila melanogaster

Chemically mediated sexual isolation between Zimbabwean endemic and cosmopolitan populations of [i]Drosophila melanogaster[/i]. ISCE 26. annual meeting

OBP19b is involved in the taste perception of amino acid in Drosophila melanogaster

Chemoperception plays a crucial role in the detection of nutritive food and avoidance of toxic compounds. It also allows animals to identify a suitable ecological niche and mating partners. As many other insects, Drosophila melanogaster possess a very sensitive chemosensory ability to detect and discriminate a wide panel of semiochemicals. Chemosensory detection is mostly mediated by olfactory and gustatory systems involving several multigene chemoreceptor families. Volatile and non-volatile chemicals compounds entering the sensory organ (sensillum) must be solubilized before being transported through the hydrophilic sensillum lymph bathing chemosensory receptors. Such “perireceptor events”…

Evolution of sexually dimorphic pheromone profiles coincides with increased number of male‐specific chemosensory organs in Drosophila prolongata

Abstract Binary communication systems that involve sex‐specific signaling and sex‐specific signal perception play a key role in sexual selection and in the evolution of sexually dimorphic traits. The driving forces and genetic changes underlying such traits can be investigated in systems where sex‐specific signaling and perception have emerged recently and show evidence of potential coevolution. A promising model is found in Drosophila prolongata, which exhibits a species‐specific increase in the number of male chemosensory bristles. We show that this transition coincides with recent evolutionary changes in cuticular hydrocarbon (CHC) profiles. Long‐chain CHCs that are sexually monomorphic …

Social experience and pheromonal perception can change male-male interactions in Drosophila melanogaster

0022-0949 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; Social interaction with conspecifics can influence the developing brain and behaviour of the exposed animal. This experience can involve the exchange and retention of visual, chemical, acoustic and tactile signals. When several Drosophila melanogaster male flies are associated with mated females in the presence of food, they show frequent aggressive interactions. To measure the role of social experience on male-male interaction, two tester males - naive or exposed to sibling(s) during a variable period of their adult development - were confronted in the absence of female and food. The two males displayed h…

Chemical Cues Influence Pupation Behavior of Drosophila simulans and Drosophila buzzatii in Nature and in the Laboratory.

International audience; In the wild, larvae of several species of Drosophila develop in heterogeneous and rapidly changing environments sharing resources as food and space. In this scenario, sensory systems contribute to detect, localize and recognize congeners and heterospecifics, and provide information about the availability of food and chemical features of environments where animals live. We investigated the behavior of D. simulans and D. buzzatii larvae to chemicals emitted by conspecific and heterospecific larvae. Our goal was to understand the role of these substances in the selection of pupation sites in the two species that cohabit within decaying prickly pear fruits (Opuntia ficus…

Genes involved in sex pheromone discrimination and their context-dependent effect

International audience

Enzymatic modulation of the bitter taste in Human and Drosophila

Enzymatic modulation of the bitter taste in Human and Drosophila. 4. International Conference on Agricultural and Biological Sciences (ABS 2018)

Revisited Roles of Drosophila Female Pheromones

All tests involved a pair of 5-day-old male and female (intact or decapitated) flies. Females were ‘homotypic’ (same species and strain as the tested male: D. melanogaster, Cs strain; D. mauritiana, 163.1 strain; D. simulans, Seychelles strain), ‘desat1 non-perfumed’ (D. melanogaster desat1 mutant), ‘perfumed’ (desat1 with transfer of Cs females pheromones), or ‘Cs’ (D. melanogaster control strain). Data shown are the frequencies of courtship (with both intact and decapitated females) and of mating (with intact females), within a 1 h observation period and were calculated from the total number of tested pairs (shown in brackets). D. mauritiana males courted (χ2 = 16.81, P < 0.001) and mated…

ARET : colloque 2018 au CSGA Dijon. 28 et 29 mai 2018 - CSGA, 9E boulevard Jeanne d'Arc, Dijon

L'Association pour la REcherche en Toxicologie (ARET) organise un colloque sur le thème "Substances odorantes et sapides : du plaisir des sens aux cibles biologiques", lundi 28 et mardi 29 mai 2018 au CSGA. Ce colloque bénéficie du soutien du département AlimH. Invité d'honneur de la table ronde: Roland Salesse.

Drosophila melanogaster glutathione transferase overexpressed in the sensory organs after exposure to bitter molecules in food

International audience

Caffeine metabolism in Drosophila melanogaster

International audience

Identification and characterization of Drosophila food-derived pheromones influencing larval behavior

Taste discrimination of pheromones in Drosophila

1095-6433 doi: DOI: 10.1016/j.cbpa.2007.01.155

P45 - Drosophila melanogaster glutathione transferase overexpressed in the sensory organs after exposure to bitter molecules in food

International audience

desat1: A Swiss army knife for pheromonal communication and reproduction?

International audience; The desat1 gene possesses an extraordinary-maybe unique-feature in the control of sensory communication systems: it codes for the two principal and complementary aspects-the emission and the reception-of Drosophila sex pheromones. These two complex aspects depend on separate genetic control indicating that desat1 pleiotropically acts on pheromonal communication. This gene also control other characters either related to reproduction and to osmoregulation. Such a functional pleiotropy may be related to the molecular structure of desat1 gene which combines a highly conserved coding region with fast evolving regulatory regions: It produces at least five transcripts all g…

The genetic variant Voila causes gustatory defects during Drosophila development

1529-2401 (Electronic) Journal Article Research Support, Non-U.S. Gov't; Voila(1), an enhancer-trap strain in Drosophila melanogaster, expresses GAL4 in most gustatory neurons, both before and after metamorphosis. Voila(1) expression starts at embryonic stage 10. In the periphery, it labels larval gustatory sensilla in the antennomaxillary complex as well as in the pharynx. GAL4 is also expressed in the CNS in a manner that prefigures expression in adult flies. Most Voila(1/1) homozygotes die between second larval instar and early adulthood. Moreover, escaping Voila(1/1) larvae do not show gustatory responses to NaCl and sucrose. The simultaneous rescue of normal larval gustation together w…

Experimental Introgression To Evaluate the Impact of Sex Specific Traits on Drosophila melanogaster Incipient Speciation

AbstractSex specific traits are involved in speciation but it is difficult to determine whether their variation initiates or reinforces sexual isolation. In some insects, speciation depends of the rapid change of expression in desaturase genes coding for sex pheromones. Two closely related desaturase genes are involved in Drosophila melanogaster pheromonal communication: desat1 affects both the production and the reception of sex pheromones while desat2 is involved in their production in flies of Zimbabwe populations. There is a strong asymmetric sexual isolation between Zimbabwe populations and all other “Cosmopolitan” populations: Zimbabwe females rarely copulate with Cosmopolitan males w…

Drosophila Food-Associated Pheromones: Effect of Experience, Genotype and Antibiotics on Larval Behavior

International audience; Animals ubiquitously use chemical signals to communicate many aspects of their social life. These chemical signals often consist of environmental cues mixed with species-specific signals-pheromones-emitted by conspecifics. During their life, insects can use pheromones to aggregate, disperse, choose a mate, or find the most suitable food source on which to lay eggs. Before pupariation, larvae of several Drosophila species migrate to food sources depending on their composition and the presence of pheromones. Some pheromones derive from microbiota gut activity and these food-associated cues can enhance larval attraction or repulsion. To explore the mechanisms underlying…

Structural and enzymatic characterization of a Drosophila melanogaster glutathione transferase overexpressed in the sensory organs after exposure to bitter molecules in food

Glutathione transferases (GSTs) are ubiquitous key detoxification enzymes that catalyze the conjugation of glutathione to a large variety of xenobiotic chemical including odorants and sapid molecules. A previous study in Drosophila melanogaster demonstrated the existence of a GST specifically expressed in the antenna and involved in signal termination by catalyzing biotransformation of odorant molecules. Genomic analysis allows identifying forty GSTs in Drosophila melanogaster but their biochemistry is poorly documented. Here we demonstrated that among the GSTs, dmelGSTD2-2 was strongly and preferentially overexpressed in the sensory organs (antennae, proboscis, legs, wings) after an exposu…

Discrimination of C18 fatty-acids by Drosophila larvae and adults

International audience

A Mutation With Major Effects on Drosophila melanogaster Sex Pheromones

0016-6731 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; Sex pheromones are intraspecific chemical signals that are crucial for mate attraction and discrimination. In Drosophila melanogaster, the predominant hydrocarbons on the cuticle of mature female and male flies are radically different and tend to stimulate or inhibit male courtship, respectively. This sexual difference depends largely upon the number of double bonds (one in males and two in females) added by desaturase enzymes. A mutation was caused by a PGal4 transposon inserted in the desat1 gene that codes for the desaturase crucial for setting these double bonds. Homozygous mutant flies produced 70-90%…

Role of xenobiotic metabolizing enzymes in the perception of caffeine in Drosophila melanogaster

Poster

Volatile Drosophila cuticular pheromones are affected by social but not sexual experience.

International audience; Recognition of conspecifics and mates is based on a variety of sensory cues that are specific to the species, sex and social status of each individual. The courtship and mating activity of Drosophila melanogaster flies is thought to depend on the olfactory perception of a male-specific volatile pheromone, cis-vaccenyl acetate (cVA), and the gustatory perception of cuticular hydrocarbons (CHs), some of which are sexually dimorphic. Using two complementary sampling methods (headspace Solid Phase Micro-Extraction [SPME] and solvent extraction) coupled with GC-MS analysis, we measured the dispersion of pheromonal CHs in the air and on the substrate around the fly. We als…

Choice alters Drosophila oviposition site preference on menthol

Summary Food choice and preference relies on multiple sensory systems that are under the control of genes and sensory experience. Exposure to specific nutrients and nutrient-related molecules can change food preference in vertebrates and invertebrates. For example, larval exposure of several holometabolous insects to menthol can change their adult response to this molecule. However, studies involving Drosophila melanogaster exposure to menthol produced controversial results due maybe to methodological differences. Here, we compared the oviposition-site preference of wild-type D. melanogaster lines freely or forcibly exposed to menthol-rich food. After 12 generations, oviposition-site prefer…

Co-adaptation of pheromone production and behavioural responses in Drosophila melanogaster males

0016-6723 (Print) Journal Article Research Support, Non-U.S. Gov't; In Drosophila melanogaster, male courtship behaviour is genetically controlled and is influenced by sex pheromones. 7-tricosene (7-T) induces a dose-dependent inhibition of male-male courtship, whereas 7,11-dienes stimulate male courtship of females. There is a geographical quantitative variation in the production of two predominant male hydrocarbons, 7-T and 7-pentacosene (7-P). We have previously found that 7-P, the main hydrocarbon from males of West African strains, stimulates males that mainly produce 7-T. Using both 'natural' and genetically engineered strains, we find that genetic factors coding for low levels of 7-P…

Une imprégnation chimio-sensorielle très précoce avec une phéromone ou des acides gras peut modifier les préférences chez l'insecte adulte

Sex-specific non-pheromonal taste receptors in Drosophila

0960-9822 (Print) Journal Article Research Support, Non-U.S. Gov't; Taste receptors have recently been reported in Drosophila [1,2], but little is known of the relation between receptor and response. Morphological studies of the distribution of chemosensory sensilla indicate that the fruit fly has two major sites of gustation: the proboscis and the legs [3]. The taste sensilla on both these sites are similar in structure and each sensillum generally houses four gustatory neurons [4]. Early anatomical observations have demonstrated a sexual dimorphism in the number of tarsal sensilla [5] and in their central projections [6]. We measured the electrophysiological responses of the prothoracic t…

Peripheral, central and behavioral responses to the cuticular pheromone bouquet in Drosophila melanogaster males.

International audience; Pheromonal communication is crucial with regard to mate choice in many animals including insects. Drosophila melanogaster flies produce a pheromonal bouquet with many cuticular hydrocarbons some of which diverge between the sexes and differently affect male courtship behavior. Cuticular pheromones have a relatively high weight and are thought to be -- mostly but not only -- detected by gustatory contact. However, the response of the peripheral and central gustatory systems to these substances remains poorly explored. We measured the effect induced by pheromonal cuticular mixtures on (i) the electrophysiological response of peripheral gustatory receptor neurons, (ii) …

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…

Role of CYP6d5 in the metabolism and the sensory perception of caffeine in Drosophila melanogaster

National audience

Characterization of Drosophila Delta glutathione transferases involved in isothiocyanate detoxification and perception

International audience

Pre-imaginal conditioning alters adult sex pheromone response in Drosophila

https://peerj.com/articles/5585/#supplemental-information; International audience; Pheromones are chemical signals that induce innate responses in individuals of the same species that may vary with physiological and developmental state. In Drosophila melanogaster, the most intensively studied pheromone is 11-cis-vaccenyl acetate (cVA), which is synthezised in the male ejaculatory bulb and is transferred to the female during copulation. Among other effects, cVA inhibits male courtship of mated females. We found that male courtship inhibition depends on the amount of cVA and this effect is reduced in male flies derived from eggs covered with low to zero levels of cVA. This effect is not obser…

The desaturase1 gene affects reproduction before, during and after copulation in Drosophila melanogaster

Desaturase1 (desat1) is one of the few genes known to be involved in the two complementary aspects of sensory communication — signal emission and signal reception — in Drosophila melanogaster. In particular, desat1 is necessary for the biosynthesis of major cuticular pheromones in both males and females. It is also involved in the male ability to discriminate sex pheromones. Each of these two sensory communication aspects depends on distinct desat1 putative regulatory regions. Here, we used (i) mutant alleles resulting from the insertion/excision of a transposable genomic element inserted in a desat1 regulatory region, and (ii) transgenics made with desat1 regulatory regions used to target …