Dopamine and sensory tissue development in Drosophila melanogaster

Abstract

Dopamine is an important signaling molecule in the nervous system; it also plays a vital role in the development of diverse non-neuronal tissues in the fruit fly Drosophila melanogaster. The current study demonstrates that males depleted of dopamine as third instar larvae (via inhibition of the biosynthetic enzyme tyrosine hydroxylase) demonstrated abnormalities in courtship behavior as adults. These defects were suggestive of abnormalities in sensory perception and/or processing. Electroretinograms (ERGs) of eyes from adults depleted of dopamine for 1 day as third instar larvae revealed diminished or absent on- and off-transients. These sensory defects were rescued by the addition of L-DOPA in conjunction with tyrosine hydroxylase inhibition during the larval stage. Depletion of dopamine in the first or second larval instar was lethal, but this was not due to a general inhibition of proliferative cells. To establish that dopamine was synthesized in tissues destined to become part of the adult sensory apparatus, transgenic lines were generated containing 1 or 4 kb of 5' upstream sequences from the Drosophila tyrosine hydroxylase gene (DTH) fused to the E. coli beta-galactosidase reporter. The DTH promoters directed expression of the reporter gene in discrete and consistent patterns within the imaginal discs, in addition to the expected expression in gonadal, brain, and cuticular tissues. The beta-galactosidase expression colocalized with tyrosine hydroxylase protein. These results are consistent with a developmental requirement for dopamine in the normal physiology of adult sensory tissues.

Increased Dopamine Level Enhances Male–Male Courtship inDrosophila

“…(1) The "preimaginal" effect could alter the development of adult sensory systems. This supports previous studies showing that that manipulation of DA during late larval developmental stage affects the formation of adult sensory nervous system (in particular, the visual system) (Neckameyer, 1996;Neckameyer et al, 2001). (2) The "adult" effect could alter the signaling role of DA in the male nervous system.…”

The Drosophila black enigma: The molecular and behavioural characterization of the black1 mutant allele

“…black is most highly expressed in the night and hdc and ebony at dawn. Mutations in the tan gene produce abnormal ERG transients, but tan has not been cloned, and defects in vesicle cycling, and visual system changes due to abnormal development (Neckameyer et al, 2001) may be as important as any postulated enzymatic activity in determining the ERG phenotype in tan mutants. A build up of free h-alanine in ebony flies, with a consequent inhibitory effect on the lamina response, is one possible explanation for the ERG differences between black and ebony.…”

“…As indicated above, the ebony gene product, NBAD synthase, is essential for NBAD formation. Neckameyer et al (2001) found that dopamine deprivation during the 3rd instar larval stage resulted in decreased or absent ERG transients in the adult fly, indicating a role for dopamine in normal visual system development. That NBAD synthase may, in vivo, form another di-peptide, halanyl histidine (carnosine) was canvassed by Hovemann et al, 1998, and more recent studies support a role in the production of h-alanyl histamine (carcinine) (Borycz et al, 2002: Richardt et al, 2003.…”

Antioxidants protect PINK1 -dependent dopaminergic neurons in Drosophila

“…Nucleotides encoding the flag-tag were designed on the reverse primer to add a C-terminal tag to PINK1. Anti-Drosophila TH antibody (1:500) was described (17). Anti-5HT antibody (1:500) was from Sigma (St. Louis, MO).…”