Fig. 4.

Phylogenetic tree (18S rRNA) of Tetrahymena species with reported CdMTs and their modular structures. Two well defined ribo-groups corresponding to both taxonomical groups were obtained. Multiple alignments of ribo-nucleotide sequences were obtained by using the T-Coffee program. Numbers indicate bootstrap values from 2000 replicates. Branch lengths are drawn to scale as indicated by the scale bar. The number of bi-, tri-, tetra- or penta- modular structures of CdMTs are indicated for each Tetrahymena group. See Table 1 for ciliate species identification