A screen for neurotransmitter transporters expressed in the visual system of Drosophila melanogaster identifies three novel genes.
The fly eye provides an attractive substrate for genetic studies, and critical transport activities for synaptic transmission and pigment biogenesis in the insect visual system remain unknown. We therefore screened for transporters in Drosophila melanogaster that are down-regulated by genetically ablating the eye. Using a large panel of transporter specific probes on Northern blots, we identified three transcripts that are down-regulated in flies lacking eye tissue. Two of these, CG13794 and CG13795, are part of a previously unknown subfamily of putative solute carriers within the neurotransmitter transporter family. The third, CG4476, is a member of a related subfamily that includes characterized nutrient transporters expressed in the insect gut. Using imprecise excision of a nearby transposable P element, we have generated a series of deletions in the CG4476 gene. In fast phototaxis assays, CG4476 mutants show a decreased behavioral response to light, and the most severe mutant behaves as if it were blind. These data suggest an unforeseen role for the "nutrient amino acid transporter" subfamily in the nervous system, and suggest new models to study transport function using the fly eye.
Romero-Calderón
Rafael
R
Interdepartmental Ph.D. Program in Neuroscience, University of California, Los Angeles, California 90095-1761, USA.
Shome
Ratula M
RM
Simon
Anne F
AF
Daniels
Richard W
RW
DiAntonio
Aaron
A
Krantz
David E
DE
D026905:Amino Acid Transport Systems / Q000235:genetics / Q000378:metabolism; D000818:Animals; D015152:Blotting, Northern; D002478:Cells, Cultured; D015536:Down-Regulation / Q000235:genetics; D004331:Drosophila melanogaster; D004596:Electroretinography; D005123:Eye / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D050485:GABA Plasma Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D050479:Neurotransmitter Transport Proteins / Q000235:genetics*; D010775:Photic Stimulation; D010802:Phylogeny; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014785:Vision, Ocular / Q000502:physiology*
D026905:Amino Acid Transport Systems; D050485:GABA Plasma Membrane Transport Proteins; D026901:Membrane Transport Proteins; D050479:Neurotransmitter Transport Proteins; D012333:RNA, Messenger; C493415:Slc6a1 protein, rat