title: Cloning metallothionein gene in Zacco platypus and its potential as an exposure biomarker against cadmium.
abstract: Zacco platypus, pale chub, is an indigenous freshwater fish of East Asia including Korea and has many useful characteristics as indicator species for water pollution. While utility of Z. platypus as an experimental species has been recognized, genetic-level information is very limited and warrants extensive research. Metallothionein (MT) is widely used and well-known biomarker for heavy metal exposure in many experimental species. In the present study, we cloned MT in Z. platypus and evaluated its utility as a biomarker for metal exposure. For this purpose, we sequenced complete complementary DNA (cDNA) of MT in Z. platypus and carried out phylogenetic analysis with its sequences. The transcription-level responses of MT gene following the exposure to CdCl2 were also assessed to validate the utility of this gene as an exposure biomarker. Analysis of cDNA sequence of MT gene demonstrated high conformity with those of other fish. MT messenger RNA (mRNA) expression and enzymatic MT content significantly increased following CdCl2 exposure in a concentration-dependent manner. The level of CdCl2 that resulted in significant MT changes in Z. platypus was within the range that was reported from other fish. The MT gene of Z. platypus sequenced in the present study can be used as a useful biomarker for heavy metal exposure in the aquatic environment of Korea and other countries where this freshwater fish species represents the ecosystem.
authors.affiliation: School of Public Health, Seoul National University, Gwanak, Seoul, 151-742, Korea.
authors.forename: Sangwoo
authors.initials: S
authors.lastname: Lee
authors.forename: Cheolmin
authors.initials: C
authors.lastname: Kim
authors.forename: Jungkon
authors.initials: J
authors.lastname: Kim
authors.forename: Woo-Keun
authors.initials: WK
authors.lastname: Kim
authors.forename: Hyun Suk
authors.initials: HS
authors.lastname: Shin
authors.forename: Eun-Suk
authors.initials: ES
authors.lastname: Lim
authors.forename: Jin Wuk
authors.initials: JW
authors.lastname: Lee
authors.forename: Sunmi
authors.initials: S
authors.lastname: Kim
authors.forename: Ki-Tae
authors.initials: KT
authors.lastname: Kim
authors.forename: Sung-Kyu
authors.initials: SK
authors.lastname: Lee
authors.forename: Cheol Young
authors.initials: CY
authors.lastname: Choi
authors.forename: Kyungho
authors.initials: K
authors.lastname: Choi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002104:Cadmium / Q000633:toxicity*; D003530:Cyprinidae / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D004784:Environmental Monitoring; D005202:Asia, Eastern; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D008099:Liver / Q000378:metabolism; D008668:Metallothionein / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D018076:DNA, Complementary; D029941:Fish Proteins; D014874:Water Pollutants, Chemical; D002104:Cadmium; D008668:Metallothionein