title: The chemosensitivity of labellar sugar receptor in female Phormia regina is paralleled with ovary maturation: Effects of serotonin.
abstract: Oogenesis in most adult insects is a nutrient-dependent process involving ingestion of both proteins and carbohydrates that ultimately depends on peripheral input from chemoreceptors. The main goal of this study was to characterize, in the female blowfly Phormia regina, the responsive changes of the labellar chemoreceptors to carbohydrates and proteins in relation to four different stages along the ovarian cycle: (1) immature ovaries, (2) mid-mature ovaries, (3) mature ovaries and ready for egg-laying and (4) post egg-laying ovaries. Then, the possible effects exerted by exogenous serotonin on the chemoreceptor sensitivity profiles were investigated. Our results show that ovary length, width and contraction rate progressively increase from stage 1 to 3, when all these parameters reach their maximum values, before declining in the next stage 4. The sensitivity of the labellar "sugar" chemoreceptors to both sucrose and proteins varies during the ovarian maturation stages, reaching a minimum for sucrose in stage 3, while that to proteins begins. Exogenous 5-HT supply specifically increases the chemoreceptor sensitivity to sugar at the stages 3 and 4, while it does not affect that to proteins. In conclusion, our results provide evidence that in female blowflies the cyclic variations in the sensitivity of the labellar chemosensilla to sugars and proteins are time-related to ovarian development and that during the stages 3 and 4 the responsiveness of the sugar cell to sucrose is under serotonergic control.
authors: Department of Biomedical Sciences, University of Cagliari, University Campus, S.P. 8, I-09042 Monserrato (CA), Italy.
authors: Paolo
authors: P
authors: Solari
authors: Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, USA.
authors: John G
authors: JG
authors: Stoffolano
authors: Department of Life and Environmental Sciences, University of Cagliari, University Campus, S.P. 8, I-09042 Monserrato (CA), Italy.
authors: Francescaelena
authors: F
authors: De Rose
authors: Department of Biomedical Sciences, University of Cagliari, University Campus, S.P. 8, I-09042 Monserrato (CA), Italy.
authors: Iole Tomassini
authors: IT
authors: Barbarossa
authors: Department of Life and Environmental Sciences, University of Cagliari, University Campus, S.P. 8, I-09042 Monserrato (CA), Italy. Electronic address: liscia@unica.it.
authors: Anna
authors: A
authors: Liscia
mesh_terms: D000818:Animals; D002628:Chemoreceptor Cells / Q000187:drug effects / Q000502:physiology*; D004175:Diptera / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D055724:Electrophysiological Phenomena; D005260:Female; D009866:Oogenesis / Q000502:physiology; D010053:Ovary / Q000254:growth & development / Q000502:physiology; D011506:Proteins / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology*; D013395:Sucrose / Q000494:pharmacology
chemical_list: D011506:Proteins; D012701:Serotonin; D013395:Sucrose
keywords: Biogenic amines; Electrophysiology; Morphology; Ovaries; Taste chemoreceptors