Phylogeny of eukaryotic aldehyde oxidases. A rooted dendrogram was obtained by the Phylip method after CLUSTAL-W computer-aided alignment of the indicated proteins. Poere AOX1 = Poecilia reticulata (guppy) AOX1; Coeel AOX1/AOX2 = Caenorhabditis elegans AOX1 and AOX2; Drome AOX1/AOX2/AOX3/AOX4 = Drosophila melanogaster AOX1, AOX2, AOX3 and AOX4; Arath AOX1/AOX2/AOX3/AOX4 = Arabidopsis thaliana AOX1, AOX2, AOX3 and AOX4; Lyces AOX1/AOX2/AOX3 = Lycopersicon esculentum (tomato) AOX1, AOX2 and AOX3; Zeama AOX1/AOX2 = Zea mays AOX1 and AOX2; Xenla AOX1 = Xenopus laevis AOX1; Gorgo AOX1 = Gorilla gorilla AOX1. All other abbreviations are as in Table 1. At present, it is unclear whether Macaca mulatta AOX4 is a functional gene product.