Fig. 2. Genomic organization of the Ceratitis capitata tra gene. (A) The top line represents the genomic DNA encompassing the Cctra locus. The positions of exons in the Cctra mRNAs are shown above the line, with Ex1, Ex2 and Ex3 representing exons in common between the male and the female mRNAs, the blue boxes representing male-specific exons, the yellow box indicating a male-specific exon in the M1 mRNA, and the red box representing a male-specific exon included in the M2 mRNA. Numbered green ovals indicate TRA/TRA-2-binding sites (see B). Introns are represented by solid lines. Open boxes represent the ORF of the female-specific 1.6 kb long mRNA (Female F1) encoding the putative 429 amino acid TRA protein (see Fig. 3). Gray boxes indicate 5' and 3' untranslated regions. Arrows above the first line represent the positions of the oligonucleotides used in the RT-PCR experiments. The bar indicates the scale of the figure. (B) Sequence alignment of eight putative TRA/TRA-2 binding sites found in the Cctra genomic sequence (see A). Conserved positions between Ceratitis and Drosophila are indicated in bold.