Larval and pheromones modulate larval food choice in Drosophila

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…

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

Identification and characterization of the first Drosophila larval pheromone

Desiccation resistance: effect of cuticular hydrocarbons and water content in Drosophila melanogaster adults

Background.The insect cuticle covers the whole body and all appendages and has bi-directionnal selective permeability: it protects against environmental stress and pathogen infection and also helps to reduce water loss. The adult cuticle is often associated with a superficial layer of fatty acid-derived molecules such as waxes and long chain hydrocarbons that prevent rapid dehydration. The waterproofing properties of cuticular hydrocarbons (CHs) depend on their chain length and desaturation number. Drosophila CH biosynthesis involves an enzymatic pathway including several elongase and desaturase enzymes. Methods.The link between desiccation resistance and CH profile remains unclear, so we t…

An olfactory receptor for food-derived odours promotes male courtship in Drosophila.

International audience; Many animals attract mating partners through the release of volatile sex pheromones, which can convey information on the species, gender and receptivity of the sender to induce innate courtship and mating behaviours by the receiver. Male Drosophila melanogaster fruitflies display stereotyped reproductive behaviours towards females, and these behaviours are controlled by the neural circuitry expressing male-specific isoforms of the transcription factor Fruitless (FRU(M)). However, the volatile pheromone ligands, receptors and olfactory sensory neurons (OSNs) that promote male courtship have not been identified in this important model organism. Here we describe a novel…

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

When Choice Makes Sense: Menthol Influence on Mating, Oviposition and Fecundity in Drosophila melanogaster

International audience; The environment to which insects have been exposed as larvae and adults can affect subsequent behaviors, such as mating, oviposition, food preference or fitness. Experience can change female preference for oviposition, particularly in phytophagous insects. In Drosophila melanogaster, females avoid laying eggs on menthol rich-food when given the choice. Exposure to menthol during larval development reduces this aversion. However, this observation was not reproduced in the following generation. Recently, we have shown that oviposition-site preference (OSP) differs between wild type D. melanogaster lines freely or forcibly exposed to menthol. After 12 generations, menth…

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…

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…

Supplemental Material for Cortot et al., 2019

The file "Cortot-SupplFigs.1-9" is a pdf containing all the Supplementary Figures 1-9 with their legendsThe file "Suppl_Tables_final" is a xlsx with Tables S1-S14 corresponding to all data shown in the Cortot et al. paper.