Fig. 3

Rate of mifepristone-induced activation of transcription. Whole mount RNA in situ hybridizations with the LexPR- (A) and EGFP-specific (B–G) antisense RNA probes. The transgenic driver-reporter line used here normally expresses EGFP in a subset of tissues shown in Fig. 2A. (A) Expression pattern of the LexPR transactivator RNA at 48 hpf. The strongest expression is found in the cell layer at the bottom of the otic capsule (possibly sensory patches) and at the olfactory bulb region. The diffused expression in the dorsal brain appears quite strong on the lateral view due to specimen thickness; the expression is actually weak as seen on the dorsal view. The 72 hpf LexPR expression pattern is similar (image not shown). (C–G) EGFP reporter transcript 1 (C), 3 (D), 6 (E), 9 (F) and 24 (G) hours after induction with 1 μM mifepristone (RU486) at 48 hpf stage onwards. No background EGFP transcript was observed without mifepristone (B).