Figure 3From: Loss of the insulator protein CTCF during nematode evolutionPresence of CTCF in basal nematodes. Phylogenetic analysis of ZF proteins from nematodes, insects, and vertebrates. The tree topology resulted from protein maximum likelihood, using the model WAG+I+G. To test the robustness of the branching pattern, three bootstrap analyses were performed with protein maximum likelihood (WAG+I+G), neighbor joining, and maximum parsimony methods. Bootstrap support values >50% are shown. Bayesian posterior probabilities, resulting from a Bayesian analysis (model: WAG+I+G), served as additional measure for the confidence of branches. Posterior probabilities >0.94 were considered as significant, lower values were ignored. Ts000x: sequence from T. spiralis, CEx: sequence from C. elegans. All putative as well as annotated CTCF and Boris orthologs form a single, well-supported clade. Note the paralogous clusters of vertebrate CTCF and vertebrate Boris [32] within this clade. No ZF protein of the derived nematode C. elegans clusters to the known CTCFs, whereas a single ZF protein of T. spiralis and CTCFs of two other basal nematodes do so. Several significantly supported clades of non-CTCF zinc finger proteins contain orthologs of both nematode genomes analysed here (Ts/CE), indicating an early diversification of ZF proteins.Back to article page