Organization of transcription units around the Drosophila melanogaster rudimentary locus and temporal pattern of expression.

The molecular organization of 90 kb of DNA derived from a region of the X chromosome that encompasses the rudimentary locus of D. melanogaster is presented. This segment spans the cytogenetic region 14F2-3 to 15A1-2, and there are, in addition to the rudimentary gene several transcription units present, whose functions are still unknown. We have determined the pattern of expression of all these genes at several stages of development, and found that they all show a different temporal modulation of their activity. The accumulation of the r product correlates well with the enzymatic activity determined for the protein product of the gene, being highest in very early embryos and adult females.