Short communication Cloning and characterization of glutathione S-transferase gene in the intertidal copepod Tigriopus japonicus and its expression after exposure to endocrine-disrupting chemicals Young-Mi Lee a , Tae-Jin Park a , Sang-Oun Jung a , Jung Soo Seo a , Heum Gi Park b , Atsushi Hagiwara c , Yong-Dal Yoon d , Jae-Seong Lee a, * a Department of Environmental Science, Graduate School, Hanyang University, Seoul 133-791, South Korea b Division of Marine Resource Development, College of Life Sciences, Kangnung National University, Gangneung 210-702, South Korea c Graduate School of Science and Technology, Nagasaki University, Nagasaki 852-8521, Japan d Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791, South Korea Abstract To investigate the impacts of marine pollution on aquatic organisms, we tested the intertidal copepod Tigriopus japonicus as a model species. To analyze the copepods’ responses to endocrine- disrupting chemicals (EDCs), we exposed them to two different chemicals: 4,4 0 -octylphenol (4,4 0 - OP, 12.5–100 lg/L for 2 h) and polychlorinated biphenyl (PCB, 6.25–25 lg/L for two days). 4,4 0 - OP was toxic, although exposure time was limited to 2 h. After extracting total RNA from the exposed T. japonicus, we performed reverse transcriptase-polymerase chain reaction (RT-PCR) to determine gene expression patterns following chemical exposure. To analyze the gene expression of T. japonicus, we used glutathione S-transferase with GAPDH as an internal control. Of the genes tested using EDC-exposed samples, 4,4 0 -OP induced upregulation of the glutathione S-transferase (GST) gene, while PCB caused downregulation of the GST gene. These results suggest that the two EDCs act in different manners in T. japonicus. Ó 2006 Elsevier Ltd. All rights reserved. 0141-1136/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.marenvres.2006.04.050 * Corresponding author. Tel.: +82 2 2220 0769; fax: +82 2 2299 9450. E-mail address: jslee2@hanyang.ac.kr (J.-S. Lee). Marine Environmental Research 62 (2006) S219–S223 www.elsevier.com/locate/marenvrev MARINE ENVIRONMENTAL RESEARCH