A TI{T-GEM.0} Trojan-Gal4 expression module has been inserted into the endogenous Sxl locus, at the 3' end of the open reading frame. This results in a Sxl-T2A-GAL4 fusion protein being expressed upon productive splicing (this pattern of splicing normally occurs in wild-type females). Auto-proteolytic cleavage of the T2A sequence results in the GAL4 protein being released from the Sxl protein, allowing it to act as a driver.
