Abstract
We have analyzed the gene expression profiles in the liver of wild common cormorants (Phalacrocorax carbo) using microarray platform, and have predicted the potential toxic effects of persistent organic pollutants (POPs) and emerging POPs. However, when applying microarray technology to wild animals, it is quite difficult to clarify the cause-andeffect relationship between accumulated contaminants and gene expression alterations. Therefore, in the present study, we isolated liver cells from wild cormorant embryos, and the cells were cultured and treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or 3,3′,4,4&prime,5-pentachlorobiphenyl (PCB126). The gene expression profiles in the cultured cells were monitored by microarray analysis, and responses to dioxins were then compared between livers (in vivo) and cultured cells (in vitro) from wild cormorants. The cultured liver cells clearly exhibited responses to the exposure of TCDD or PCB126 including inductions of cytochrome P450 1A genes. Whereas fifteen genes on the microarray showed similar effects between in vivo and in vitro tests, indicating that these genes might be affected directly by dioxin exposure, the responses of other genes were different between wild cormorant livers and cultured cells. Therefore, we compared the ‘biological process’ gene ontology (GO) terms of dioxin-responsive genes between in vivo and in vitro tests. The most of annotated GO terms were shared in the livers and cultured cells, implying that the effects by dioxins were similar between both groups. Thus, gene expression profiling in the cells isolated from cormorants might be useful for evaluating chemical effects on the wild population.
