Fig. 1

Molecular organization and sex-specific transcript of tra genes from B. dorsalis (a) and B. correcta (b). Both genes contain five common exons (dark gray boxes); however, there are four and two male-specific (ms) exons (light gray boxes) in Bdtra and Bctra, respectively. Introns are lines connecting exon boxes. The start codon (atg) is indicated in the common exon 1B while the conceptually alternative stop codons are either located in the downstream male-specific exons or in common exon 3 for the female transcript.