Molecular organization of the rudimentary gene of Drosophila melanogaster.

We have determined the molecular structure of the rudimentary gene of Drosophila melanogaster. The transcription unit, which extends over 14,000 bases, is split into seven exons and six introns. Sequences presenting homologies with a TATA box and a CAT box are located upstream from the transcription initiation site, and there is a consensus polyadenylation signal in the vicinity of the 3' end of the messenger RNA coding sequence. Short intronic sequences fit well with consensus signals found in other eukaryotic genes and involved in the splicing of the precursor messenger RNA. Partial genomic and complementary DNA sequencing has revealed stretches of amino acid sequence homologies with the corresponding enzymes in Saccharomyces cerevisiae and Escherichia coli. This is in good agreement with the genetic map of the locus, which indicates that the enzymic activities encoded by the gene are organized linearly along the DNA.