Figure 5: The transcribing probability near Bcd-responsive promoter of hb is decreased in dmpd embryos.

(a) Shown is an image of hb intron staining from a cycle 14 embryo. Nuclear envelope is shown in red and intron dots in green. Scale bar, 50 μm. A magnified view of a section of the expression domain is shown on the right side of this panel. (b) Shown is a computer-processed image of panel (a). Here each of the identified nuclei is shown in a colour according to the number of intron dots detected inside. White, blue and green represent zero, one and two intron dots detected, respectively. (c) Shown is the plot of ρ as a function of x/L based on panel b. (d–i) Shown are the mean ρ profiles from wt and dmpd embryos at time classes t1–t6. The mean and s.d. of ρ_plat for t1–t6 time classes are: 0.50±0.07; 0.84±0.04; 1.03±0.08; 0.71±0.14; 0.52±0.10; 0.34±0.03 for wt embryos (n=3, 3, 7, 7, 5 and 4, respectively) and 0.51±0.11; 0.86±0.25; 0.79±0.21; 0.54±0.06; 0.38±0.12; 0.23±0.05 for dmpd embryos (n=3, 4, 5, 5, 5 and 4), respectively. The P-values (from Student’s t-tests) between wt and dmpd embryos for t1–t6 time classes are: 0.93; 0.92; 0.016; 0.028; 0.078; 0.0087, respectively. The mean ρ at x/L ~0.15 (which is located outside of the plateau domain for calculating ρ_plat) appears higher in dmpd embryos than in wt embryos at t6 (i); this is likely caused by an ‘outlier’ dmpd embryo that has a very high level of ρ at this location (see Supplementary Fig. S8f).