Figure 3

ecmA and ecmB expression domains and P . pallidum homologues. (A) Expression domains of subregions of the D. discoideum ecmA and ecmB promoters, with PstO and PstA denoting expression from the distal PstO and proximal PstA regions of the ecmA promoter, respectively, and PstB and PstAB denoting expression from the distal basal disc, upper and lower cup region and the proximal stalk region of the ecmB promoter, respectively. The PstB cells sort to both the upper cup and the lower cup and basal disc of the fruiting body, while the PstO cells sort to the upper cup [8, 24, 25]. The cells that express ecmA and/or ecmB in the prespore region are collectively called anterior-like cells. (B) Protein sequences of the six top hits for a BLASTp search of the P. pallidum genome with D. discoideum EcmA and EcmB sequences were aligned with EcmA and EcmB, using Clustal Omega with five combined iterations [26]. The alignment was subjected to Bayesian phylogenetic inference until convergence had been reached, using a mixed amino acid model with a proportion of invariable sites [27]. The resulting tree is rooted at the midpoint between the most divergent sequences and shows the posterior probabilities of the interior nodes. The bar represents 0.1 substitutions per site.