Figure 3. Origins of complexes and pathways of bilaterian cell types.

Reference cellular structures from human and other vertebrates are depicted here for comparative purposes. Gene products are coloured in by their node of origin as per Fig. 1. White text denotes known oncogenes or tumour suppressor genes. Genes with eumetazoan origin are found in either Nematostella or Trichoplax or both. a, Cell adhesion and polarity in epithelia. The asterisk indicates that collagen IV genes have not been found in the Amphimedon genome but have been reported as present in the homoscleromorph sponge Pseudocorticium jarrei⁴⁷. b, Synaptic and signalling elements in neurons.