Fig. 8. (A) The nucleotide and deduced amino acid sequences of the carbonic anhydrase (CA) fragment cloned from African lungfish Protopterus annectens blood, together with (B) a phylogenetic tree to illustrate the relationship between this lungfish CA (highlighted in black) and selected vertebrate cytoplasmic CA isoforms. The phylogenetic tree was constructed using neighbour-joining analysis (see Materials and methods for more detail), and was ordered using Drosophila CA (GenBank protein accession AAY56645) as a monophyletic outgroup. Horizontal branch lengths are scaled to represent the relative number of amino acid substitutions occurring along a branch, and support values at the nodes are indicated as a percentage from bootstrap analysis using 100 pseudoreplicates. GenBank protein accession numbers for the sequences used in the tree were as follows. CA I: mouse AAH11223, rat XP_226922, human AAH27890; CA II: mouse AAA37357, rat CAA41227, human AAA51909, Xenopus CAJ83242; CA III: mouse NP_031632, rat AAA40846, human AAA52293, CA XIII: mouse NP_078771, rat XP_222295, human NP_940986; fish cytoplasmic CAs: lamprey AAZ83742, gar AAM94169, tilapia AAQ89896, rainbow trout blood isoform (CAb) AAP73748, rainbow trout cytoplasmic isoform (CAc) AAR99329, zebrafish¹ NP_571185, zebrafish² NP_954685, Japanese dace BAB83090, and carp AAZ83743. Sequences obtained from GenBank were truncated appropriately so as to use only the region that overlapped with the lungfish CAb sequence.