Fig. 5.

Analysis of images of fixed Drosophila embryos. (A) Images of Drosophila embryos stained for nuclei (gray), Twi (green) and dpERK (red). Scale bar: ∼50 μm (images have been rescaled to remove slight interembryo size variations). Each image is of a different embryo arrested at a different developmental time and in a different rotational orientation. (B) Data from A, registered and ordered using vector diffusion maps. The ‘expert rank’ for each image is indicated. (C) A representative developmental trajectory obtained from local averaging of the entire set of registered and ordered images (see smooth trajectories from registered and ordered images in the supplementary material). (D) Correlation between the image ranks calculated from the vector diffusion maps algorithm and the ranks obtained from ordering by an expert. The rank correlation coefficient is 0.9716.