Figure 6.

Direct estimation for the positional information carried by Hunchback. (A) Extrapolation in sample size for different bin sizes Δ, starting with 10 bins for the bottom line and increasing to 50 bins for the top line in increments of 2. Black points are averages of naive estimates over 100 random choices of m embryos (error bars = SD), plotted against 1/m on the x-axis. Lines and blue circles represent extrapolations to the infinite data limit, m → ∞. (B) The extrapolations to the infinite data limit (blue points from A) are plotted as a function of the bin size, and the second regression is performed (blue line) to find the extrapolation of Δ → 0. The final estimate, represented by the red square, is I^DIR(hb; x) = 2.26 ± 0.04 bits; the error bar is the statistical uncertainty in the extrapolated value due to limited sample size.