Search results for "ASTER"
showing 10 items of 2223 documents
INHIBITION OF FATTY ACID DESATURASES INDrosophila melanogasterLARVAE BLOCKS FEEDING AND DEVELOPMENTAL PROGRESSION
2016
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…
Regulation of cuticular hydrocarbon profile maturation by Drosophila tanning hormone, bursicon, and its interaction with desaturase activity
2016
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…
Gene Regulation and Species-Specific Evolution of Free Flight Odor Tracking in Drosophila
2018
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 …
Dietary rescue of altered metabolism gene reveals unexpected [i]Drosophila[/i] mating cues
2015
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…
A Mutation With Major Effects on Drosophila melanogaster Sex Pheromones
2005
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%…
desat1 and the Evolution of Pheromonal Communication in Drosophila
2009
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…
desat1: A Swiss army knife for pheromonal communication and reproduction?
2012
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 consequences of regulation of desat1 expression for pheromone emission and detection in Drosophila melanogaster.
2010
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…
Nonlinear response theory for Markov processes: simple models for glassy relaxation.
2012
The theory of nonlinear response for Markov processes obeying a master equation is formulated in terms of time-dependent perturbation theory for the Green's functions and general expressions for the response functions up to third order in the external field are given. The nonlinear response is calculated for a model of dipole reorientations in an asymmetric double well potential, a standard model in the field of dielectric spectroscopy. The static nonlinear response is finite with the exception of a certain temperature $T_0$ determined by the value of the asymmetry. In a narrow temperature range around $T_0$, the modulus of the frequency-dependent cubic response shows a peak at a frequency …
Economic Adaptation to Risky Environment in the Late Middle Ages: The Case of the "Accrues" of the Doubs in Chaussin (Jura, France) from c. 1370 to c…
2017
Located along the meanders of the Doubs, the people of Chaussin had to deal with the particular impact of the river on their environment. Due to the impact of the Little Ice Age on water levels in the area, the Doubs sometimes had special floods, which frequently changed its course from the end of the fourteenth century. As a result, some lands were absorbed, and others emerged, which were called the “accrues.” From 1377 the first observation of lost lands appears in the accounts of the castellan, in a petition from landowners who did not want to pay taxes on these fields. More than twenty years later, in the first decade of the fifteenth century, the duke of Burgundy, facing the same situa…