Fig. 4

Phylogenetic relationships between Pat J, LIN and DLG proteins based on their L27 and two first PDZ domain (except for LIN proteins which have a single PDZ) sequences. Available bilaterian sequences and predicted cnidarian, poriferan, placozoan and ctenophoran sequences were aligned with MAFFT v7.123b. The consensus phylogenetic tree was computed with PhyML and MrBayes. Both analyses were run under a LG evolution model with a gamma distribution and 4 rate categories. A total of 1 million generations, sampled every 1000 generations with a burn-in of 250 was used for the bayesian analysis. Bayesian posterior probabilities are shown in black and 100-bootstap PhyML replicates are shown in blue for each branch. Low- scoring L27 domains were also included in the alignment. Canonical domain architecture is depicted for PATJ-MUPP1, LIN and DLG family protein. We identified with high confidence Dlg orthologous genes coding for specific domains (Lin2 and Lin7 binding domain (L27), GUK, SH3 and three PDZ domains) in all sponges and in T. adhaerens (even though the L27 domain is missing). In ctenophores, Dlg orthologous genes were found without GUK domain. In Porifera, we found that all species possess PatJ homologues that cluster with bilaterian PatJ. In contrast, no PatJ homologue was found in ctenophores