Distinct octopamine cell population residing in the CNS abdominal ganglion controls ovulation in Drosophila melanogaster

Dev Biol. 2003 Dec 1;264(1):38-49. doi: 10.1016/j.ydbio.2003.07.019.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic alpha-Agonists / metabolism*
  • Animals
  • Animals, Genetically Modified
  • Central Nervous System / cytology
  • Central Nervous System / metabolism
  • Drosophila melanogaster / anatomy & histology
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / physiology*
  • Enhancer Elements, Genetic
  • Female
  • Ganglia, Invertebrate / cytology*
  • Ganglia, Invertebrate / metabolism
  • HSP70 Heat-Shock Proteins / genetics
  • Infertility, Female
  • Mixed Function Oxygenases / genetics
  • Mixed Function Oxygenases / metabolism*
  • Neurons / cytology
  • Neurons / metabolism
  • Octopamine / metabolism*
  • Ovary / cytology
  • Ovary / metabolism
  • Ovulation / physiology
  • Phenotype
  • Promoter Regions, Genetic
  • Transgenes

Substances

  • Adrenergic alpha-Agonists
  • HSP70 Heat-Shock Proteins
  • Octopamine
  • Mixed Function Oxygenases
  • tyramine beta-hydroxylase