A DROSOPHILA 3RD CHROMOSOME MINUTE LOCUS ENCODES A RIBOSOMAL-PROTEIN

Minutes (M) are a group of over 50 phenotypically similar Drosophila m utations widely believed to affect ribosomal protein genes, This repor t describes the characterization of the P element-induced M(3)95A(Plac 92) mutation [allelic to M(3)95A]. This mutation can be reversed by th e mobilization of the P element, demonstrating that the mutation is ca used by insertion of this transposable element. The gene interrupted b y insertion of the P element was cloned by use of inverse polymerase c hain reaction. Nucleotide sequence analysis revealed 70-75% identity t o the human and rat ribosomal protein S3 genes, and to the Xenopus rib osomal protein S1a gene. At the amino acid level, the overall identity is approximate to 78% for all three species. This is only the second time that a Minute has been demonstrated to encode a ribosomal protein .