Fig. 5.

Map of chiffon gene structure. Schematic of chiffon locus showing nearby genes including cactus. The gene structure for chiffon is shown in the inset shaded box as coding sequences (black boxes), untranslated regions (gray boxes), and introns (lines). There are three annotated splice isoforms for chiffon: RA encodes a 1711-aa protein; RB and RD encode 1695-aa proteins from a single ∼5 kb exon. An overlapping gene, CG42231, shares a promoter with chiffon but differs in its reading frame and encodes a separate polypeptide. The genomic regions deleted/mutated in each of the indicated chiffon alleles (chiffon^DsRed, chiffon^ETBE3 and chiffon^WF24) are shown by the dashed line arrows. The chiffon rescue transgenes are shown by the black boxes at the base of the panel. Rescue constructs contain the indicated chiffon 5′ and 3′ regulatory regions (black boxes) and the chiffon coding sequences. The conserved Dbf4 N-terminal domain and C-terminal insect-specific Gcn5-binding domain are indicated by the shaded boxes overlaying the rescue constructs, and the position of each nonsense mutation in the rescue constructs is indicated by an asterisk.