Figure 2.

The mof transgene driven by a tubulin promoter is a target for MSL1 and overcomes the requirement for MSL3. (A) Tubulin-driven mof gene. (B,C) Tubulin-driven mof gene (tub > y⁺ > mof) containing a yellow gene cassette between the promoter and the gene such that mof expression becomes inducible upon excision of the yellow gene cassette by expression of flippase. Recruitment of MSL1 before (B) and after (C) excision is shown. (D) Same as in A, however, in this case the transgenic line carrying tub-mof was crossed into the msl-3⁰⁸³ mutant background by using females mutant for msl-3⁰⁸³ expressing low levels of MSL2 from an Hsp83 promoter. Recruitment of MSL1 to the tub-mof transgene is indicated by an arrow. The position of the endogenous mof gene is shown by an asterisk. Red cross (×) represents no transcription. DNA was stained with Hoechst 322 (blue).