(c) Hierarchical clustering of apical Venus::HE5 expression from one representative experiment showing behaviour in the same area over time; columns represent fluctuations in Venus::HES5 intensity in small local areas (bands) obtained by dividing the spatial signal into non-overlapping 20μm regions and normalizing to the mean and standard deviation of each region over time (z-scoring); data has been subject to a Gaussian blur pre-processing step (see Appendix Figure S2b and Methods). 