Fig. 1. The repression of larval limbs and Dll transcription is highly dependent on Ubx concentration. (A) The repression of Keilin's organs (in black) and the sensory hairs (red) of Keilin's organs as a function of ectopic Ubx concentration in the thorax. Each data point represents a different ectopic expression experiment, within which at least 120 larval limb phenotypes were scored and then averaged. Error bars: standard error of the mean for the limb repression values and 95% confidence intervals for Ubx concentration and Dll repression values. (B) The repression of sensory hairs (red) and Dll transcriptional repression (blue) plotted against Ubx concentration. (C) Dll transcriptional repression as a function of ectopic Ubx levels in the anterior (red) and posterior (blue) compartments of the thoracic segments. (D-F) Ubx protein expression in mid-stage 11 embryos of the following genotypes: (D) wild type, (E) ectopically expressed Ubx at 76% of endogenous levels and (F) ectopically expressed Ubx at 32% of endogenous levels. Ubx protein was detected by staining with FP3.38 anti-Ubx antibody. White ovals indicate the positions where Ubx protein levels were measured. (G,H) Transcripts of Dll (red) and wg (green) in the limb fields of (G) wild-type embryos, and (H) embryos expressing ectopic Ubx at 32% of endogenous levels. In all figures, anterior is towards the left and dorsal is upwards.