Figure 2.

Sxl gene structure & products. Schematic illustrating the portion of the 11 exon ~20 kb Sxl gene that gives rise to the three major classes of sex-specific transcripts through the differential use of two promoters and alternative splicing. The embryo-specific exon (E1) is blue. The translation-terminating male-specific third exon is red. Other exons are gray. The mechanism that drives splicing of the SxlPe pre-mRNAs such that exon E1 is joined directly to exon 4 is not understood.¹⁰⁵,¹⁰⁶