title: A new brain dopamine-deficient Drosophila and its pharmacological and genetic rescue.
abstract: Dopamine (DA) is a neurotransmitter with conserved behavioral roles between invertebrate and vertebrate animals. In addition to its neural functions, in insects DA is a critical substrate for cuticle pigmentation and hardening. Drosophila tyrosine hydroxylase (DTH) is the rate limiting enzyme for DA biosynthesis. Viable brain DA-deficient flies were previously generated using tissue-selective GAL4-UAS binary expression rescue of a DTH null mutation and these flies show specific behavioral impairments. To circumvent the limitations of rescue via binary expression, here we achieve rescue utilizing genomically integrated mutant DTH. As expected, our DA-deficient flies have no detectable DTH or DA in the brain, and show reduced locomotor activity. This deficit can be rescued by l-DOPA/carbidopa feeding, similar to human Parkinson's disease treatment. Genetic rescue via GAL4/UAS-DTH was also successful, although this required the generation of a new UAS-DTH1 transgene devoid of most untranslated regions, as existing UAS-DTH transgenes express in the brain without a Gal4 driver via endogenous regulatory elements. A surprising finding of our newly constructed UAS-DTH1m is that it expresses DTH at an undetectable level when regulated by dopaminergic GAL4 drivers even when fully rescuing DA, indicating that DTH immunostaining is not necessarily a valid marker for DA expression. This finding necessitated optimizing DA immunohistochemistry, showing details of DA innervation to the mushroom body and the central complex. When DA rescue is limited to specific DA neurons, DA does not diffuse beyond the DTH-expressing terminals, such that DA signaling can be limited to very specific brain regions.
authors.affiliation: Department of Biology, University of Virginia, Charlottesville.
authors.forename: K
authors.identifier: 0000-0001-5926-3663
authors.initials: K
authors.lastname: Cichewicz
authors.affiliation: Department of Biology, University of Virginia, Charlottesville.
authors.forename: E J
authors.initials: EJ
authors.lastname: Garren
authors.affiliation: Department of Biology, University of Virginia, Charlottesville.
authors.forename: C
authors.initials: C
authors.lastname: Adiele
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Aso
authors.affiliation: Department of Biology, University of Virginia, Charlottesville.
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Biology, University of Virginia, Charlottesville.
authors.forename: M
authors.initials: M
authors.lastname: Wu
authors.affiliation: Genes, Circuits, Rhythms and Neuropathology, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, Paris, France.
authors.forename: S
authors.initials: S
authors.lastname: Birman
authors.affiliation: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
authors.forename: G M
authors.initials: GM
authors.lastname: Rubin
authors.affiliation: Department of Biology, University of Virginia, Charlottesville.
authors.forename: J
authors.initials: J
authors.lastname: Hirsh
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D004195:Disease Models, Animal; D004298:Dopamine / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D059290:Dopaminergic Neurons / Q000378:metabolism; D004330:Drosophila / Q000235:genetics / Q000378:metabolism*; D007980:Levodopa / Q000378:metabolism; D008297:Male; D018377:Neurotransmitter Agents / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics / Q000378:metabolism
chemical_list: D018377:Neurotransmitter Agents; D007980:Levodopa; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine
keywords: Carbiodopa; Dopamine deficiency; Drosophila; Drosophila behavior; Parkinson's disease; central complex; dopamine rescue; genetic model of Parkinson's disease; l-DOPA; mushroom body