title: Regulation of cuticular hydrocarbon profile maturation by Drosophila tanning hormone, bursicon, and its interaction with desaturase activity.
abstract: 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 is known about the timecourse of changes in CH profile and about the role of bursicon in this process. Here we show in Drosophila that rk function is also required for the normal maturation of the fly's CH profile, with flies mutant for rk function showing dramatically elevated levels of CHs. Interestingly, this effect is mostly abrogated by mutations in the Δ9 desaturase encoded by the desaturase1 gene, which introduces a first double bond into elongated fatty-acid chains, suggesting that desaturase1 acts downstream of rk. In addition, flies mutant for rk showed changes in the absolute and relative levels of specific 7-monoenes (in males) and 7,11-dienes (in females). The fact that these differences in CH amounts were obtained using extractions of very different durations suggests that the particular CH profile of flies mutant for rk is not simply due to their unsclerotized cuticle but that bursicon may be involved in the process of CH biosynthesis itself.
authors: Centro Interdiciplinario de Neurociencias de Valparaiso, Universidad de Valparaiso, Valparaíso, Chile.
authors: Justin
authors: J
authors: Flaven-Pouchon
authors: Centre des Sciences du Goût et de l'Alimentation, UMR 6265 CNRS, UMR 1324 INRA, Université de Bourgogne-Franche-Comté 6, Bd Gabriel, F-21000 Dijon, France.
authors: Jean-Pierre
authors: JP
authors: Farine
authors: Centro Interdiciplinario de Neurociencias de Valparaiso, Universidad de Valparaiso, Valparaíso, Chile. Electronic address: john.ewer@uv.cl.
authors: John
authors: J
authors: Ewer
authors: Centre des Sciences du Goût et de l'Alimentation, UMR 6265 CNRS, UMR 1324 INRA, Université de Bourgogne-Franche-Comté 6, Bd Gabriel, F-21000 Dijon, France. Electronic address: jean-francois.ferveur@u-bourgogne.fr.
authors: Jean-François
authors: JF
authors: Ferveur
mesh_terms: D000818:Animals; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D044943:Fatty Acid Desaturases / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D006838:Hydrocarbons / Q000378:metabolism; D007447:Invertebrate Hormones / Q000378:metabolism*; D008297:Male; D010858:Pigmentation; D043562:Receptors, G-Protein-Coupled / Q000235:genetics* / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D006838:Hydrocarbons; D007447:Invertebrate Hormones; D043562:Receptors, G-Protein-Coupled; C416853:Rk protein, Drosophila; C002295:bursicon; D044943:Fatty Acid Desaturases; C408225:desat1 protein, Drosophila
keywords: Eclosion; Exoskeleton; Insect; Molting; Neurohormone; cis-Vaccenyl acetate