Differential gene expression profiling in bisphenol A exposed Oryzias javanicus, a fish species highly adaptable to environmental salinity

Abstract

We investigated the effects of the environmental pollutant bisphenol A (BPA; an endocrine disrupting chemical) on gene expression levels in the fish species Oryzias javanicus (the Javanese medaka) acclimated to different salinities. We used cDNA microarrays to compare gene expression in O. javanicus exposed to BPA in seawater and freshwater. Within the genus Oryzias, O. javanicus is highly adaptable to various environmental salinities. Using this species we detected the induction of differential expression of genes by BPA, and compared the transcriptional changes caused by chemical exposure at different salinities. Of the 289 genes that were induced, 244 were repressed by a factor of more than two in O. javanicus exposed to BPA in seawater, and 101 genes were induced and 114 genes were repressed by a factor of more than two in O. javanicus exposed to BPA in freshwater. The expression of 78 genes, most of which are involved in cellular processes and signaling, was changed by exposure to BPA in both seawater and freshwater. The gene most upregulated in O. javanicus exposed to BPA in seawater was glutathione S transferase, while the decorin gene was the most upregulated gene in O. javanicus exposed to BPA in freshwater: for each gene the expression level was approximately seven times greater than in control fish. For the fish in seawater the most downregulated gene was proline-rich protein 6,used cDNA microarrays to compare gene expression in O. javanicus exposed to BPA in seawater and freshwater. Within the genus Oryzias, O. javanicus is highly adaptable to various environmental salinities. Using this species we detected the induction of differential expression of genes by BPA, and compared the transcriptional changes caused by chemical exposure at different salinities. Of the 289 genes that were induced, 244 were repressed by a factor of more than two in O. javanicus exposed to BPA in seawater, and 101 genes were induced and 11