Expression of a Drosophila melanogaster acetylcholine receptor-related gene in the central nervous system.

We isolated Drosophila melanogaster genomic sequences with nucleotide and amino acid sequence homology to subunits of vertebrate acetylcholine receptor by hybridization with a Torpedo acetylcholine receptor subunit cDNA probe. Five introns are present in the portion of the Drosophila gene encoding the unprocessed protein and are positionally conserved relative to the human acetylcholine receptor alpha-subunit gene. The Drosophila genomic clone hybridized to salivary gland polytene chromosome 3L within region 64B and was termed AChR64B. A 3-kilobase poly(A)-containing transcript complementary to the AChR64B clone was readily detectable by RNA blot hybridizations during midembryogenesis, during metamorphosis, and in newly enclosed adults. AChR64B transcripts were localized to the cellular regions of the central nervous system during embryonic, larval, pupal, and adult stages of development. During metamorphosis, a temporal relationship between the morphogenesis of the optic lobe and expression of AChR64B transcripts was observed.