Phylogenetic tree of the cullin gene family. Phylogenetic tree based on the alignment of cullins of Homo sapiens (Hs), Mus musculus (Mm), Rattus norvegicus (Rn), Drosophila melanogaster (Dm) and Caenorhabditis elegans (Ce). Gene IDs are as listed in Table 1. ClustalX was used to align sequences using the standard settings. The tree was drawn using Figtree v1.3.1. The bar indicates the proportion of amino acid sites at which two compared sequences are different. Iso, isoform.