CYP9E2, CYP4C21 and related pseudogenes from German cockroaches, Blattella germanica: implications for molecular evolution, expression studies and nomenclature of P450s

The cDNAs of two novel P450s (CYP9E2 and CYP4C21) were isolated from German cockroaches, Blattella germanica. Both CYP9E2 and CYP4C21 are typical microsomal P450s and their deduced amino acid sequences share a number of common characteristics with other members of the P450 superfamily. Northern blot analyses using a CYP9E2 or CYP4C21 probe showed that 'CYP9E2' and 'CYP4C21' were expressed at all life stages. Two pseudogenes related to CYP9E2 and three pseudogenes related to CYP4C21 were also isolated. These represent the first P450 pseudogenes from an insect other than Drosophila melanogaster. The relative number of P450 pseudogenes in B. germanica is apparently higher than in D. melanogaster. The implications of these results for the molecular evolution, expression studies and nomenclature of P450s are discussed.