Fig. 1.

A: dsc73 (green bar, top figure) maps distal to the argos gene (red bar, top figure) and encodes a single transcript with five exons (boxed areas, bottom figure). The open reading frame (green areas inside boxed region, bottom figure) encodes 852 residues. An inactivating P-element insertion in dsc73, l(3)j10E8, maps within the 5′untranslated region and an inactivating Piggy-bac element insertion in dsc73, l(3)e01027, maps ~4.8 kb upstream of the splice acceptor site of exon 2. B: The open reading frame of dsc73 has an N-terminal signal sequence (blue), several N-linked gycosylation consensus sites (red), and four repeats of CXCPX(1-2) aromatic (brown). The sequence with yellow background was used to generate antiserum to Dsc73. The sequence with green background is the most highly conserved and highly structured domain of the protein. C: A 147-residue domain in Dsc73 is conserved in all insects and in the arthropod Daphnia pulex. Of interest, this domain spans four exons in Drosophila melanogaster. The exon boundaries are indicated by arrows.