Identification of differentially expressed genes in liver of marine medaka fish exposed to benzo[a]pyrene

Abstract

The construction of a subtractive cDNA library of organisms and the analysis thereof have proven meaningful in the search for clones whose expressions are regulated by exterior changes. The principal objective of this study was to identify the differentially expressed genes of marine medaka fish (Oryzias javanicus) under benzo[a]pyrene exposure conditions. Medaka fish were exposed to 100 μg/L of benzo[a]pyrene for 24 hr and its hepatic RNA was extracted; RNA from the livers of non-exposed medaka fish was also extracted. Both RNAs were employed in the construction of the subtractive cDNA library and the nucleotide sequences of differentially expressed clones were analyzed. Twenty-eight genes of the total differentially expressed clones were considered significant; in particular, the transcription of the cytochrome P450 1A gene was upregulated in a dose-dependent manner under various benzo[a]pyrene concentration exposure conditions. The 28 genes were then divided into 4 categories: (1) information storage and processing, (2) cellular processes and signaling, (3) metabolism, and (4) poorly characterized. The data reported herein provide general information regarding the effects of benzo[a]pyrene contamination on marine organisms, and constitute a primary step in the development of novel biomarkers for marine environmental pollution. © 2011 Korean Society of Environmental Risk Assessment and Health Science and Springer.