Altered Gene Expression Profile in Medaka Fish by Acute Toxicity of Polychlorinated biphenyls

Abstract

Differential gene expression profiling was carried out in the liver tissue of medaka fish, Oryzias latipes, after exposure to Arochlor, polychlorinated biphenyls (PCBs), which were used as coolants and insulating fluids for transformers and capacitors; classified as persistent organic pollutants, using a medaka cDNA microarray. Twenty seven kinds of differentially expressed candidate genes, with 13 and 14 induced and repressed in their gene expressions, respectively, were associated with cytoskeleton (3, 11.1%), development (1, 3.7%), endocrine (1, 3.7%), immune (3, 11.1%), metabolism (6, 26.0%), nucleic acid/protein binding (3, 11.1%), reproduction (6, 22.2%), signal transduction (2, 7.4%) and non-categorized (1, 3.7%). Of these genes, changes at the transcription level of 13 genes were re-evaluated by real-time quantitative PCR (qRT-PCR). Considering the known function of authentic genes, the effects of PCBs on the biological activity and pathological aspects in medaka fish were discussed. The identified genes could be used as molecular biomarkers for biological responses to PCBs contamination in an aquatic environment.