Fig. 2

Phylogenetic relationship of Xenopus Ceacam proteins. Phylogenetic trees were constructed based on mature N domain amino acid sequences (signal peptides excluded) from X. tropicalis (a) and X. laevis Ceacams (b) using the Maximum Likelihood method (MEGA6 software). The tree with the highest log likelihood is shown. The percentage of trees in which the protein sequences clustered together is shown next to the branches. For Ceacams predicted to contain more than one N domain, only the most N-terminal N1 domains were included in the analysis. Two distantly related Ceacam groups of N domains termed group 1 and group 2 can be discriminated in both species. Some of the most closely related Ceacams in the allotetraploid X. laevis represent homeologs located on the small (S) or the large (L) version of chromosome 7. A closely related pair of paralogous proteins termed .1 and .2 is found on chromosome 7S but not on chromosome 7 L. The bar below the phylogenetic tree shows the scale for the number of substitutions per site. P, pseudogene; Xla, X. laevis; Xtr, X. tropicalis