Endocrine disruption effects in cadmium exposed marine medaka fish (Oryzias javanicus)

Abstract

Transcripts response induced by acute toxicity of cadmium (Cd) in marine medaka was evaluated. The median lethal concentration of the animals (LC50) was determined to be 27.8 mg/L after exposure to Cd for 48 h. Differential gene expression profiling of the marine medaka was performed with a cDNA microarray after exposure to 300 &micro g/L of Cd (about 1/100 of 48-h LC50) for 48 h to understand the acute toxicity of Cd. We identified 774 differentially expressed genes the expressions of 440 genes were up-regulated and those of 334 genes were down-regulated over 1.5-fold (P < 0.05). The up-regulated and down-regulated genes were assembled into 24 and 22 functional groups, respectively, based on the eukaryotic orthologous groups (KOG) classification. The differentially expressed gene profile of Cd exposed fish was compared with that of bisphenol A (BPA) and 17β-estradiol (E2). Thirty-two genes were common in three experimental groups, and these genes could be categorized to carcinogenesis, detoxification, endocrine disruption, immune, inorganic ion transport, lipid metabolism, membrane signal receptor, spermatogenesis, transcriptional factor, transmembrane glycoprotein receptor, and other biological responses. The results showed that Cd could induce the endocrine disruption in fish species.profiling of the marine medaka was performed with a cDNA microarray after exposure to 300 &micro g/L of Cd (about 1/100 of 48-h LC50) for 48 h to understand the acute toxicity of Cd. We identified 774 differentially expressed genes the expressions of 440 genes were up-regulated and those of 334 genes were down-regulated over 1.5-fold (P < 0.05). The up-regulated and down-regulated genes were assembled into 24 and 22 functional groups, respectively, based on the eukaryotic orthologous groups (KOG) classification. The differentially expressed gene profile of Cd exposed fish was compared with that of bisphenol A (BPA) and 17β-estradiol (E2). Thirty-two genes were common in three experimental groups, and these genes could be categorized to carcinogenesis, detoxification, endocrine disruption, immune, inorganic ion transport, lipid metabolism, membrane signal receptor, spermatogenesis, transcriptional factor, transmembrane glycoprotein receptor, and other biological responses. The results showed that Cd could induce the endocrine disruption in fish species.