Figure 6

Phylogeny of β2 subunit genes. Phylogenetic tree showing the relationships among β2 subunit core domain (SH3 – GK) sequences. Numbers above the nodes indicate maximum likelihood quartet puzzling support values; numbers below the nodes are maximum parsimony bootstrap proportions. "---" indicates a node that was unresolved in the maximum parsimony analysis. The long branch associated with zebrafish β2.2 reflects an elevated rate of amino acid substitution throughout the core domain, particularly at the 5' end. See Methods for accession numbers of sequences used.