title: Cadmium affects the expression of heat shock protein 90 and metallothionein mRNA in the Pacific oyster, Crassostrea gigas.
abstract: Cadmium (Cd) is a widespread nonessential heavy metal that enters the aquatic environment as a result of natural processes and human activities such as wastewater production, agriculture, and mining. To determine the effects of Cd on organisms, we investigated its time- and dose-related effects on mRNA levels of heat shock protein 90 (HSP90) and metallothionein (MT) in the gill and digestive gland and changes enzyme levels in the hemolymph of the Pacific oyster Crassostrea gigas. Full-length HSP90 cDNA was isolated from C. gigas by rapid amplification of cDNA end (RACE) techniques and found to contain 2154 nucleotides, including an open reading frame, and was predicted to encode a protein of 717 amino acids. BLAST analysis indicated that the HSP90 gene of C. gigas shared high homology with known HSP90 genes of other mollusks. The expression of HSP90 mRNA increased significantly with exposure to 0.01 ppm Cd for 11 days or 0.05 or 0.1 ppm Cd for 7 days. The expression of MT mRNA increased significantly with exposure to 0.01, 0.05, or 0.1 ppm Cd for 11 days. Glutamate oxaloacetate and glutamate pyruvate levels increased significantly with exposure to 0.05 or 0.1 ppm Cd for 7 days. These results indicate that HSP90 and MT play important roles in the physiological changes related to metabolism and cell protection that occur in Pacific oysters exposed to Cd.
authors.affiliation: Division of Marine Environment & Bioscience, Korea Maritime University, Busan, 606-791, South Korea.
authors.forename: Yong Ki
authors.initials: YK
authors.lastname: Choi
authors.forename: Pil Gue
authors.initials: PG
authors.lastname: Jo
authors.forename: Cheol Young
authors.initials: CY
authors.lastname: Choi
mesh_terms: D000410:Alanine Transaminase / Q000097:blood; D000595:Amino Acid Sequence; D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood; D019256:Cadmium Chloride / Q000633:toxicity*; D049896:Crassostrea / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D004064:Digestive System / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring / Q000379:methods; D005880:Gills / Q000187:drug effects / Q000378:metabolism; D005971:Glutamates / Q000097:blood; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006458:Hemolymph / Q000187:drug effects / Q000201:enzymology; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010071:Oxaloacetates / Q000097:blood; D011773:Pyruvates / Q000097:blood; D012333:RNA, Messenger / Q000378:metabolism*; D013997:Time Factors; D015854:Up-Regulation; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D005971:Glutamates; D018841:HSP90 Heat-Shock Proteins; D010071:Oxaloacetates; D011773:Pyruvates; D012333:RNA, Messenger; D014874:Water Pollutants, Chemical; D008668:Metallothionein; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D019256:Cadmium Chloride