Cloning and tissue expression of cytochrome P450 1B1 and 1C1 genes from Javanese Medaka, Oryzias Javanicus, under environmental stress conditions

Abstract

Cytochrome P450 1 (CYP1) is widely used as an indicator of exposure to environmental contaminants. In the study, two full-length complementary DNAs encode for CYP1B1 and CYP1C1 were cloned from medaka liver exposed to 500 ppb β-naphthoflavone for 24 h. CYP1B1, having 1984 bp, contains an open reading frame of 1551 bp encoding a protein of 517 amino acids; while, CYP1C1 having 2601 bp consists of an open reading frame of 1578 bp encoded for 525 amino acid residues. The highest levels of these CYP1 genes transcript were observed in intestine and the lowest in liver from the fish fed on fuel oil-contaminated feed. Javanese medaka CYP1B1 and CYP1C1 transcripts were detected in the gill, muscle and liver when transferred from seawater to freshwater with the highest level of expression in gill and muscle. Starvations for one week tended to down- regulate the Javanese medaka CYP1 expression.

Keywords: Cytochrome P450, Javanese medaka, salinity, starvation, heavy fuel oil, cloning, expression

African Journal of Biotechnology, Vol 13(20), 2028-2040