Figure 2

Evolutionary relationship between members of the SR family. The phylogeny was inferred using the neighbor-joining method. ClustalW was used to align sequences and perform phylogenetic analysis. Trees were drawn by CTree. The horizontal lines in each panel indicate the similarity between SR proteins. (a) Phylogenetic tree based on the alignment of the human (Hs) SR protein family. The numbers above each bar indicate the degree of similarity. (b) Phylogenetic tree based on the alignment of Homo sapiens (Hs), Drosophila melanogaster (Dm), Caenorhabditis elegans (Ce), Arabidopsis thaliana (At), and Schizosaccharomyces pombe (Sp) SR protein sequences. Green and blue lines indicate different clusters. Cluster set selection is based on minimizing the subtype diversity ratio, a measure that groups related subclasses.