Figure 1. The Bmdsx mini gene system. The mini gene (not shown to scale) contains Bmdsx exons 1, 2, 3, 4, and 5 and encodes the entire open reading frame. Introns 2, 3, and 4 have been internally shortened. The mini gene has an 8bp fragment, which is the 5' end of intron5. The arrow indicates the site of transcription initiation within the ie1 sequences. The length of each intron is indicated in nucleotides. Open boxes: common exons. Shaded boxes: female specific exons. Lines between boxes: introns.