Figure 3—figure supplement 2.

For the model parameter l_max, which is the length at which an airineme stops searching if it has not yet found a target, we wondered whether a single number would be appropriate or whether we needed to use a distribution to capture the variability of airineme lengths. We measure the experimental quantity l_final, which is the length of airinemes when they stop growing, whether or not they have made contact with a target cell, shown in red in (A, B) (N=56 airinemes). We run simulations in which target cells are randomly placed according to 2D Poisson statistics with mean distance dtarg=50μm and measured their length distribution when they stop growing l_final, shown in blue in (A, C) (again, whether or not they have made contact with a target). We find that the distributions for experimental data and simulated data agree qualitatively when lmax=250μm. Note that the variability in both experimental and simulated distributions is of similar magnitude, suggesting that the randomness in observed airineme length arises from the randomness in target cell placement.