ISOLATION OF A CYTOCHROME-P450 3A CDNA SEQUENCE (CYP3A30) FROM THE MARINE TELEOST FUNDULUS-HETEROCLITUS AND PHYLOGENETIC ANALYSES OF CYP3A GENES

A reverse transcriptase polymerase chain reaction (RT-PCR) protocol, u sing degenerate PCR-primers specific to highly conserved regions of ma mmalian CYP3A genes, was employed to amplify a 400 base pair cDNA frag ment from Fundulus heteroclitus liver RNA, The 124 amino acid sequence deduced from this cDNA sequence was aligned with corresponding sequen ces from representative members from the CYP1, 2, 3, and 4 gene famili es retrieved from the GenBank database. Phylogenetic trees were constr ucted using distance-matrix and maximum parsimony methods. The F. hete roclitus sequence and all mammalian CYP3A sequences cluster together w hen compared to sequences of members of CYP gene families 1, 2, and 4. This fish sequence was 57 to 70% identical to the corresponding regio n of mammalian CYP3A genes. These data indicate that the sequence obta ined from F. heteroclitus represents a teleost fish CYP3A gene and it has been designated CYP3A30. (C) 1997 Academic Press.