Figure 2

The Allen Developing Mouse Brain Reference Atlas ontology hierarchy through level 5. Each ontological term corresponds to a node in the hierarchy, labeled by the abbreviation followed by the level number inside a parenthesis. The nodes are color-coded as in the original atlas in Figure 1. The transverse segments lie at level 3, and they are combined with the longitudinal zones at level 5 to generate the grid-like pattern. We up-propagate the voxel annotations to levels 1, 3, and 5, respectively, in our experiments in order to study the gene expressions in the grid-like longitudinal and transversal domains.