Metallothionein mRNA expression in freshwater teleost, Channa punctata (Bloch) under the influence of heavy metal, cadmium – a dose kinetic study

Abstract

Increased Metallothionein(MT) synthesis is associated with increased capacity for binding metals such as copper, zinc and cadmium, as well as protection against metal toxicity. A study was carried out using quantitative real-time reverse-transcriptase polymerase chain reaction (q-RT-PCR) in freshwater teleost, Channa punctata (Bloch), after exposure to sub-lethal concentrations of cadmium. Post 14 days exposure, the heightened MT mRNA expression was seen only in kidney, whereas in contaminated liver and gills, the MT gene expression collapsed significantly below the basal level. The difference in the effect of various concentrations of cadmium on MT mRNA transcript level in the tissues under study was found significant. The study indicates that the expression of MT mRNA in C. punctata occurs in tissue specific and dose dependent manner.