title: Distinct octopamine cell population residing in the CNS abdominal ganglion controls ovulation in Drosophila melanogaster.
abstract: Octopamine is an important neuroactive substance that modulates several physiological functions and behaviors of invertebrate species. Its biosynthesis involves two steps, one of which is catalyzed by Tyramine beta-hydroxylase enzyme (TBH). The Tbetah gene has been previously cloned from Drosophila melanogaster, and null mutations have been generated resulting in octopamine-less flies that show profound female sterility. Here, I show that ovulation process is defective in the mutant females resulting in blockage of mature oocytes within the ovaries. The phenotype is conditionally rescued by expressing a Tbetah cDNA under the control of a hsp70 promoter in adult females. Fertility of the mutant females is also restored when TBH is expressed, via the GAL4-UAS system, in cells of the CNS abdominal ganglion that express TBH and produce octopamine. This neuronal population differs from the dopamine- and serotonin-expressing cells indicating distinct patterns of expression and function of the three substances in the region. Finally, I demonstrate that these TBH-expressing cells project to the periphery where they innervate the ovaries and the oviducts of the reproductive system. The above results point to a neuronal focus that can synthesize and release octopamine in specific sites of the female reproductive system where the amine is required to trigger ovulation.
authors: Institute of Molecular Biology and Biotechnology, Foundation of Research and Technology-Hellas, 71110 Heraklion, Crete, Greece. monastir@imbb.forth.gr
authors: Maria
authors: M
authors: Monastirioti
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000378:metabolism*; D000818:Animals; D030801:Animals, Genetically Modified; D002490:Central Nervous System / Q000166:cytology / Q000378:metabolism; D004331:Drosophila melanogaster / Q000033:anatomy & histology / Q000235:genetics / Q000502:physiology*; D004742:Enhancer Elements, Genetic; D005260:Female; D017952:Ganglia, Invertebrate / Q000166:cytology* / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D007247:Infertility, Female; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D009655:Octopamine / Q000378:metabolism*; D010053:Ovary / Q000166:cytology / Q000378:metabolism; D010060:Ovulation / Q000502:physiology; D010641:Phenotype; D011401:Promoter Regions, Genetic; D019076:Transgenes
chemical_list: D000316:Adrenergic alpha-Agonists; D018840:HSP70 Heat-Shock Proteins; D009655:Octopamine; D006899:Mixed Function Oxygenases; C023205:tyramine beta-hydroxylase