Molecular Characterization of Cytochrome P450 1A (CYP1A) in Asian
Sea bass (Lates calcalifer Bloch) and Its Application as a Biomarker in the
Gulf of Thailand
Affiliations: Department of Aquatic Science, Faculty of Science,
Burapha University, Chonburi 20131, Thailand; and The Center of Excellence on
Environmental Health, Toxicology & Management of Chemicals, Bangkok,
Thailand | Institute of Marine Science, Burapha University,
Chonburi 20131, Thailand | University of Gothenburg, Department of Zoology, P.O.
Box 463, SE 405 30, Göteborg, Sweden
Abstract: This study focusses on aquatic pollution in Thailand, using
induction of hepatic cytochrome P450 1A (CYP1A) in Asian sea bass as a
biomarker to assess exposure to polyaromatic hydrocarbons (PAHs). Polyclonal
antibodies (PAb) were raised against Asian sea bass CYP1A in mice. Western blot
analyses revealed that these antibodies recognized a CYP1A protein in Asian sea
bass treated with benzo[a]pyrene (BaP). The presence of a CYP1A orthologue in
Asian sea bass liver was confirmed by isolating a partial cDNA, using a reverse
transcriptase polymerase chain reaction (RT-PCR) approach. Quantitative RT-PCR
analysis revealed that CYP1A mRNA was 2.5-fold higher in fish injected with
BaP. The PAb were next applied on 15 different tropical fish species, caught
off the Chonburi from three different stations: (1) Koh Loi, Si Racha, (2) Ao
Udom and (3) Laem chabang. Although, species variation in CYP1A protein levels
was observed, the data suggest that Si Racha and Ao Udom were more contaminated
with PAH-type contaminants compared with Laem chabang. This study confirm
studies in temperate waters that CYP1A could be used as early indicators of
PAH-type exposure in Thailand, and that PAb against Asian sea bass is suitable
for analyses of CYP1A in different tropical fish species.
Keywords: Thailand, PAH, benzo[a]pyrene, CYP1A, Asian sea bass, tropical fish
