Functional Sxl gene product in Drosophila leads to:
Functional Sxl protein present exclusively in XX individuals where X:A ratio equals 1.0 drives female developmental program. Active Sxl protein autoregulates maintenance of its own productive splicing, avoiding exon 3 inclusion, and forces splicing of transformer into functional Tra protein. Tra together with constitutive Tra2 directs female-specific splicing of doublesex producing DsxF transcription factor that activates yolk protein genes, female genitalia and represses male genes, while male-specific dosage compensation via hypertranscription is turned off. Consequently XX flies develop as
Ref: Gilbert, Developmental Biology, 12th ed., Chapter 7: Sxl initiates female splicing cascade in Drosophila.
