Neighbour-joining phylogeny of the P450 sequences from the honeybee (in red) with selected P450s from D. melanogaster (Dm – green) and An. gambiae (Ag – blue). The outgroup (P450cam, the camphor hydroxylase from Pseudomonas putida), human CYP2J2 and CYP3A4, and two other P450s mentioned in the text (CYP4S4 from Mamestra brassicae and CYP4AW1 fom Phyllopertha diversa, both possibly involved in odour or pheromone clearance) are marked in blue. Orthologues of the D. melanogaster Halloween gene products involved in ecdysteroid biosynthesis (phm, spo, dib, shd, sad) and of the nompH gene product are marked on the right, as well as the CYP15 sequences orthologous to the juvenile hormone epoxidase identified in the cockroach. Two additional series of orthologues (CYP4AA1 and CYP301A1) of unknown function are marked by a hatch (#). The great diversity of the fruit fly and mosquito CYP3 and CYP4 clades and mitochondrial CYP12 family (see ) is represented by just a few members for clarity of the tree. Inclusion of the other members does not alter the overall topology of the tree. Distance bootstrap values of greater than 50% (1000 replicates) are indicated at the relevant nodes by an asterisk (*).