Search results for "Drosophila melanogaster"
showing 10 items of 426 documents
Cholinergic Control of Synchronized Seminal Emissions in Drosophila
2004
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…
A set of female pheromones affects reproduction before, during and after mating in Drosophila
2004
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…
Genetic feminization of pheromones and its behavioral consequences in Drosophila males
1997
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…
Insulin signalling mediates the response to male-induced harm in female Drosophila melanogaster.
2016
Genetic manipulations in nutrient-sensing pathways are known to both extend lifespan and modify responses to environmental stressors (e.g., starvation, oxidative and thermal stresses), suggesting that similar mechanisms regulate lifespan and stress resistance. However, despite being a key factor reducing female lifespan and affecting female fitness, male-induced harm has rarely been considered as a stressor mediated by nutrient sensing pathways. We explored whether a lifespan-extending manipulation also modifies female resistance to male-induced harm. To do so, we used long-lived female Drosophila melanogaster that had their insulin signalling pathway downregulated by genetically ablating t…
A Drosophila male pheromone affects female sexual receptivity.
2006
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…
Genetic feminization of brain structures and changed sexual orientation in male Drosophila
1995
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…
Sex-specific non-pheromonal taste receptors in Drosophila
2000
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…
Larval competition in Drosophila melanogaster: effects on development time
1990
The effects on development time of larval competition that is interrupted at different times are analyzed in an experiment with constant larval density and varying proportions of two competing strains. Interruption of competition is carried out by means of the overfeeding technique, which allows for the study of individuals that, after several days under competition stress, either complete their development in crowded conditions or migrate to a vial with fresh food where the rest of their development takes place. Results of mean development time and within-vial variance of development time show that individuals under strong competition stress can arrest their development retaining the capab…
The genetic variant Voila causes gustatory defects during Drosophila development
2000
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…
Genetic and biochemical characterization of little isoxanthopterin (lix), a gene controlling dihydropterin oxidase activity in Drosophila melanogaste…
1991
Dihydropterin oxidase catalyses the oxidation of 7,8-dihydropteridines into their fully oxidized products, and is involved in the biosynthesis of isoxanthopterin. Fifteen Drosophila melanogaster mutants, selected for their low pterin and isoxanthopterin content, were assayed for dihydropterin oxidase activity. The activity was around 100% in most mutants tested, slightly reduced in red, g and dke, and undetectable in lix. In flies carrying various doses of the lix+ allele, a correlation was found between enzyme activity and the number of lix+ copies in the genome. The results suggest that lix is the structural gene for the dihydropterin oxidase enzyme. Isoxanthopterin was quantitated in str…