Figure 3. Method of 4-dimensional tomographic imaging identifies collective cellular behaviors and complex tissue boundaries.(A) In silico cell lineage tracing with the virtual reference embryo identified the coordinated processes of cell proliferation, differentiation and migration. Neural progenitor cells (red color coded, Supplementary movie 10) started with proliferation at the anterior and the posterior regions of the embryo (Fig. 4A, Neuron ①-②). Pharynx progenitor cells (green color coded, Supplementary movie 12) were specified in the anterior body part of the embryo then began with proliferation (Pharynx ①-②). They became regionalized and formed a convex polygon shape in contacts with the neurons, the muscle and the intestine precursor cells (Pharynx ③-④). The hypodermis and neuron cells (purple color coded, Supplementary movie 13) were specified in the ventral embryo body part along the V-D axis (Hypodermis and neuron ①-②). They contributed to the development of the future body wall and the sensory organs of the animal (Hypodermis and neuron ③-④). (B) Serial section computer images were generated from the point cloud model color coded according to cell lineage type, which define the tissue boundaries. Representative slice computer images obtained at different sectioning positions and time points were presented.