Figure 20: Cytochrome P450 protein families in mouse, human and pufferfish.

a, Phylogenetic tree, based on the neighbour-joining method²⁹⁷, applied to the alignment of the whole P450 protein family. Each triangle represents a cytochrome P450 family cluster. Asterisks next to a triangle represent mouse pseudogenes defined by the presence of either an in-frame stop codon or a frameshift. The colour codes are indicated in the lower-right panel. When the family presents one member in each of the studied organisms, the triangle is labelled in orange. The height of the triangle is proportional to the number of proteins, which is indicated by white-line subdivisions. Chromosomal ___location in mouse is shown on each of the branches for each subfamily. The lengths of the branches are not drawn to scale. Branches with significant nodes (bootstrapping value >0.7) are in black, with the remainder in blue. In 6 out of the 15 CYP2C family cases, the localization of the genomic region from which they are derived remains unassigned. b, Detailed phylogenetic tree of the CYP2C family based on the neighbour-joining method. The root of the tree was determined using a CYP2A sequence as out-group. Eight out of the 15 mouse CYP2C sequences are excluded in this tree as they are very short. Sequence identifiers are coloured on the basis of their source: red, mouse; green, human. Sequence identifiers followed by an asterisk indicate that the sequences contain either a premature in-frame stop codon or frameshift. Bootstrap values are shown at the branches. Colour codes of branches are as for a. Although the bootstrap value for the branch containing CYP2C pseudogene2 and ENSP00000285979 is rather low (0.579), it might seem that CYP2C pseudogene2 has only recently lost its function, as a putative orthologue in human (ENSP00000285979) is still clustered with it.