Figure 2

Sequence relationships of 35 deduced A. thaliana AQP protein sequences. The tree was constructed using the Clustal-X/TreeView programs [40,41]. Four subfamilies can be identified; HsAQP1 (human AQP1) and E. coli GLP-F (a glycerol facilitator protein) are included in black as outgroups. The length of each branch is proportional to the divergence of that protein sequence from other members of the family. The distance scale represents the evolutionary distance, expressed as the number of substitutions per amino acid. Thus each PIP is more similar to the other members of this subgroup than are the TIPs and NIPs/SIPs.