Ligand binding properties of OBP28a, a recombinant odorant binding protein from Drosophila melanogaster

National audience; Odorant binding proteins (OBPs) are small (around 14 kDa) soluble proteins isolated from the sensory organs of a wide range of insect species. OBP reversely bind odorants with dissociation constants in the micromolar range and are good candidate for transporting hydrophobic odorant molecules to olfactory receptors, through the aqueous sensillar lymph. In the genome of Drosophila melanogaster, 52 OBPs with high sequence divergence have been identified. Amongst them, OBP28a is one of the most abundant odorant binding proteins suggesting an important physiological role. A recent study proposed a novel role for this OBP in buffering changes in the odor environment (Larter et …

Genetic feminization of pheromones and its behavioral consequences in Drosophila males

0036-8075 (Print) Journal Article Research Support, Non-U.S. Gov't; Pheromones are intraspecific chemical signals important for mate attraction and discrimination. In the fruit fly Drosophila melanogaster, hydrocarbons on the cuticular surface of the animal are sexually dimorphic in both their occurrence and their effects: Female-specific molecules stimulate male sexual excitation, whereas the predominant male-specific molecule tends to inhibit male excitation. Complete feminization of the pheromone mixture produced by males was induced by targeted expression of the transformer gene in adult oenocytes (subcuticular abdominal cells) or by ubiquitous expression during early imaginal life. The…

Genetic feminization of brain structures and changed sexual orientation in male Drosophila

0036-8075 (Print) Journal Article Research Support, Non-U.S. Gov't; The neural basis of sexual orientation in Drosophila was studied by the production of males with regionally feminized brains. Such flies express the female form of the sex determination gene transformer in a limited number of neurons under the control of GAL4 enhancer trap inserts. This method facilitated the creation of lines with a stable pattern of feminization. In tests of sexual preferences, flies that were feminized in a portion of the antennal lobes or in a subset of the corpora pedunculata (mushroom bodies) courted both males and females. These two brain structures, both of which are involved in olfactory processing…

Simultaneous influence on male courtship of stimulatory and inhibitory pheromones produced by live sex-mosaic Drosophila melanogaster

0962-8452 (Print) Journal Article Research Support, Non-U.S. Gov't; Stable strains of Drosophila melanogaster flies producing mosaic sex-pheromones were created by manipulating the sex-determination gene transformer in different cellular patterns. Chromosomally male flies produced molecules that were partly or totally feminized, depending upon the strain. The influence on male courtship behaviour of live flies producing different mixtures of male and female pheromones was measured. The intensity of the male response was mainly a function of the stimulatory effect of 7, 11 nonacosadiene and 7, 11 heptacosadiene, two female pheromones, combined with the inhibiting effect of 7-tricosene, the m…

Multisensory perception of dietary faty-acids in Drosophila.

International audience; Fatty-acids (FAs) are crucial for animal survival and reproduction. However, our knowledge of the mechanisms underlying the perception and preference of dietary FA is limited, particularly in invertebrates. We obtained behavioral data with wild-type Drosophila melanogaster larvae and adults showing a clear preference to some of the FAs tested (C14:0, C16:0, C18:0, C18:1, C18:2, C18:3). These data, based on tests involving both individuals and groups, showed that larvae prefer desaturated FAs whereas adults prefer saturated FAs. Moreover, we found that larval and adult responses relied on olfaction and taste modalities, and maybe also on mechanoperception [1]. We will…

A set of female pheromones affects reproduction before, during and after mating in Drosophila

0022-0949 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; Sex pheromones are chemical signals used for mate attraction and discrimination in many invertebrate species. These compounds are often complex mixtures with different components having different effects. We tested live Drosophila melanogaster mutant female flies genetically depleted for unsaturated cuticular hydrocarbons, which were then perfumed with these substances to measure their influence on various aspects of reproduction. Female pheromones of the control Cs strain enhanced female attractivity, copulation duration and tended to decrease the number of female progeny of mutant females mated with Cs m…

Discrimination of C18 fatty acids by Drosophila melanogaster larvae and adults (wild-type strain, Dijon 2000)

International audience

Nerd, a locus on chromosome III, affects male reproductive behavior in Drosophila melanogaster

0028-1042 (Print) Journal Article

Insect-food pheromone interaction

Expression of the desat1 gene in neural and non-neural tissues separately affect sex pheromone perception and emission in Drosophila melanogaster

International audience; Animals often use sex pheromones for mate choice and reproduction. As for other signals, the genetic control of the emission and perception of sex pheromones must be tightly coadapted, and yet we still have no worked-out example of how these two aspects interact. Most models suggest that emission and perception rely on separate genetic control. We have identified a Drosophila melanogaster gene, desat1, that is involved in both the emission and the perception of sex pheromones. To explore the mechanism whereby these two aspects of communication interact, we investigated the relationship between the molecular structure, tissue-specific expression, and pheromonal phenot…

The pheromonal role of cuticular hydrocarbons in Drosophila melanogaster

0265-9247 (Print) Journal Article Research Support, Non-U.S. Gov't Review; Pheromones play a crucial role in mate stimulation and discrimination. In the fruit fly Drosophila, the most abundant cuticular hydrocarbons act as sex pheromones during courtship behavior. There are several active molecules and they compose a sex- and species-specific pheromonal bouquet. Different species from the Drosophila melanogaster subgroup have adopted alternative systems of chemical mate recognition. Recent exploration of these interspecific variations, and of intraspecific variations, has led to the characterization of genes and to the mapping of structures that process the production and perception of chem…

La drosophile change ses préférences envers les acides gras au cours de sa vie.

Intra- and intergenerational exposition to dietary fatty-acids affects behavior and fitness in D. melanogaster

Intra- and intergenerational exposition to dietary fatty-acids affects behavior and fitness in D. melanogaster. ESITO 13. meeting

Mapping of genetic loci that change pheromone discrimination in Drosophila males

0016-6723 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; Reproduction in individual animals of sexual species depends largely upon their ability to detect and distinguish specific signal(s) among those produced by various potential sexual partners. In Drosophila melanogaster males, there is a natural polymorphism for discrimination of female and male principal pheromones that segregates with chromosome 3. We have mapped two loci on chromosome 3 that change sex-pheromone discrimination in males. We successively exploited meiotic recombination, deficiencies and enhancer-trap strains; excision of the transposon in two selected enhancer-trap strains clearly reverted…

Genetic control of male cuticular hydrocarbons in Drosophila melanogaster

0016-6723 (Print) Comparative Study Journal Article; 7-tricosene (7-T) and 7-pentacosene (7-P) are the two main hydrocarbons on the cuticle of male Drosophila melanogaster. These two substances might play a pheromonal role during courtship behaviour. We investigated the genetic basis of the quantitative polymorphism observed in the production of 7-T and 7-P. Strains of different geographic origin, with males producing either predominantly 7-T or predominantly 7-P, were hybridized with strains carrying genetic markers. We found that chromosome II changes the balance between 7-T and 7-P while chromosome III regulates the overall quantity of both 7-monoenes. We have also characterized and roug…

A single mutation alters production and discrimination of Drosophila sex pheromones

0962-8452 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; The evolution of communication is a fundamental biological problem. The genetic control of the signal and its reception must be tightly coadapted, especially in inter-individual sexual communication. However, there is very little experimental evidence for tight genetic linkage connecting the emission of a signal and its reception. We found that a single genomic transposon inserted in the desatl gene of Drosophila melanogaster simultaneously affected the emission and the perception of sex-specific signals. This mutation greatly decreased the production of unsaturated hydrocarbons on the cuticle of mature fl…

Genetic control of pheromones in Drosophila simulans. I. Ngbo, a locus on the second chromosome

0016-6731 (Print) Journal Article; 7-Tricosene and 7-pentacosene are predominant hydrocarbons on the cuticle of both sexes in Drosophila simulans. The pheromonal role of 7-tricosene has been clearly established for conspecific males, while a synergistic effect for 7-pentacosene has been postulated. Interstrain variation for the production of both compounds is very marked, but similar for both sexes. The genetic basis of this polymorphism was investigated. A major role was found for the second chromosome, which controls the 7-tricosene:7-pentacosene ratio. The main locus involved in controlling this variation, Ngbo, was mapped to position 65.3 on the second chromosome. The production of 7-pe…

Taste, movement, and death: varying effects of new prospero mutants during Drosophila development

0022-3034 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; The PGal4 transposon inserted upstream of the pan-neural gene prospero (pros) causes several neural and behavioral defects in the Voila(1) strain. The precise excision of the transposon simultaneously rescued all these defects whereas its unprecise excision created new pros(V) alleles, including the null allele pros(V17). Here, we describe the relationship between the genetic structure of pros locus, larval locomotion, and larval gustatory response. These two behaviors showed varying degrees of variation depending upon the pros allele. We also found a good relation between behavioral alteration, the level …

Saturated and unsaturated fatty acids: behavioural responses and plasticity fatty acids as relevant stimuli in Drosophila?

Saturated and unsaturated fatty acids: behavioural responses and plasticity fatty acids as relevant stimuli in [i]Drosophila[/i]?. 13. rencontre du club de neurobiologie des invertébrés

Genetic control of pheromones in Drosophila simulans. II. kete, a locus on the X chromosome

0016-6731 (Print) Journal Article; The production of Drosophila cuticular hydrocarbons, including contact pheromones, is under polygenic control. To investigate X-linked loci, EMS mutations were induced in Drosophila simulans flies. A mutant strain was discovered which in both sexes show a reduction in the biosynthesis of both 7-tricosene (7-T) the species contact pheromone and all other linear hydrocarbons. The locus controlling this effect, kete, is recessive and was localized to I, 18.5. Unlike a previously identified gene on the second chromosome of this species, Ngbo, kete does not affect the ratio of 7-T:7-pentacosene (7-P). Other reproductive characteristics are also affected, includ…