Fig. 5

Diagram depicting the proposed evolutionary history of cadherin subfamily members in echinoderms. All cadherin subfamily members, which contain cadherin repeat (CA) domains, are depicted using blue, purple, or red rectangles. Classical cadherins are defined as cadherins that contain predicted intracellular p120 and beta-catenin-binding motifs. Both atypical cadherins and protocadherins lack these motifs, but protocadherins are defined as proteins that contain 6–7 CA domains. The ancient bilaterian cadherin toolkit suggested by our phylogenetic analysis is depicted using a yellow box. Additions, losses, or modifications of the proteins within this toolkit are depicted using black tick marks on the tree branches. Protein additions are represented using plus signs ( +), while losses are represented using minus signs (−). The conversion of a protein from one cadherin subfamily to a different classification is depicted using an arrow. If branch-specific loss is not noted for a taxon on the diagram, it is assumed that organism contains all the proteins within the ancient bilaterian cadherin toolkit. CDH23 = cadherin-23, CDH88C = cadherin-88C, CSTN1 = calsyntenin-1, DCHS2 = dachsous-2, Fat1 = fat atypical cadherin 1, Fat4 = fat atypical cadherin 4, GCDH = G-cadherin, PCDH9 = protocadherin-9, PCDH15 = protocadherin-15, UECDH = uncharacterized echinoderm cadherin