Expression of ion channel genes in Drosophila.

Ion channel transcripts from three genes were localized by the method of tissue in situ hybridization. The genes examined were the Drosophila Na+ channel genes, paralytic (para) and Drosophila Sodium Channel (DSC), and the K+ channel gene, Shaker( Sh). All three of the genes were expressed in cell bodies of the fly central nervous system, including optic lobes, central brain, suboesophageal ganglion, and thoracico-abdominal ganglion. Sh was additionally expressed in the photoreceptor cells of the retina and pupal flight muscle, while para and DSC were not. The temporal expression pattern of Sh in muscle was different from that in the central nervous system: muscle expression was transient and limited to mid-pupal stage while nervous system expression was observed throughout pupation, apparently peaking at the late-pupal stage. Only one class of 5' end was found in pupal muscle, possibly indicating regulation of splicing pathways.