Figure 7.

Ectopic expression of stripe and mef2, but not delilah, induces STV. All embryos shown are at stage 16 and viewed dorsally or dorso-laterally. A, C, E, and G are stained with anti-STV and B, D, F, H are stained with anti-Alien. (A and B) w¹¹¹⁸ control embryos. (C and D) enGAL4; UASstripe embryos. (E and F) enGAL4; UASdelilah embryos. (G and H) enGAL4; UASmef2 embryos. STV is clearly induced by ectopic stripe (C), but not by ectopic delilah (E). Ectopic mef2 is also sufficient to induce ectopic STV in the ectoderm (G). The irregularity of engrailed domains in the enGAL4; UASmef2 embryos is due to ectopic mef2 affecting the patterning of the epidermis and disrupting dorsal closure. Ectopic alien expression is not induced in an enGAL4; UASmef2 embryo (H), showing that the ectopic induction of stv by mef2 is not a consequence of induction of ectopic tendon cells.