Figure 3.—

Ecdysone-induced transcription is delayed and reduced in Elp3 mutants. Total RNA was prepared from whole larvae 4 days AEL and daily until pupariation occurred. cDNA either was synthesized for quantitative RT-PCR analysis or RNA (10 μg) was subjected to Northern analysis. (A) E74A transcription is not induced to detectable levels in Elp3 larvae (left), while Fbp1 is induced slowly from 8 days until maximal levels are reached at 12 days AEL (right). The level of transcription is very low compared to the control. Numbers on y-axes (and above bars) are in arbitrary units from RT-PCR. nd, not determined. (B) Northern analysis of Broad Complex transcript. A probe from the core region of BR-C was used. Expression is induced to a high level at 5 days AEL in wild type (lane 1), while very weak induction is observed at 12 days AEL in the mutant (lane 9). (C) Other tested genes are expressed at normal levels in the Elp3 mutant. All numbers obtained from RT-PCRs were first normalized to actin. The expression in Elp3 mutant is shown relative to the level in heterozygotes (dashed line). E74A and Fbp1 (from A) are shown for comparison.