Beschreibung:
<jats:p><jats:bold>Abstract: </jats:bold> The <jats:italic>Drosophila</jats:italic>γ‐aminobutyric acid (GABA) receptor subunit gene <jats:italic>Rdl</jats:italic> was isolated on the basis of a mutant phenotype showing high levels of insensitivity to picrotoxinin and cyclodiene insecticides. Following analysis of two dissimilar cDNAs isolated from the locus, we report that <jats:italic>Rdl</jats:italic> undergoes extensive alternative splicing at two locations in the putative extracellular domain. At each location a choice is made between exons of the same size: “a'’or “b'’(23 amino acids long with two substitutions) and “c'’or “D'’(46 residues long with 10 substitutions). The function of these alternative exons remains unclear; however, exon d contains a putative site for casein kinase II phosphorylation. AH possible combinations of exons (a with c or d and b with c or d) were found in RNA isolated from early embryos. This is the first demonstration of alternative splicing in a GABA receptor gene from invertebrates.</jats:p>