mRNA expression of a cadmium-responsive gene is a sensitive biomarker of cadmium exposure in the soil collembolan Folsomia candida

作者：Nakamori Taizo^*; Fujimori Akira; Kinoshita Keiji; Ban nai Tadaaki; Kubota Yoshihisa; Yoshida Satoshi

来源：Environmental Pollution, 2010, 158(5): 1689-1695.

DOI：10.1016/j.envpol.2009.11.022

• cDNA
• Collembola
• Gene expression
• Metallothionein
• Oxidative stress

The gene expression of environmental organisms is useful as a biomarker of environmental pollution. One of its advantages is high sensitivity. We identified the cDNA of a novel cadmium-responsive gene in the soil collembolan Folsomia candida. The deduced protein, designated "metallothionein-like motif containing protein" (MTC), was cysteine-rich and contained a metallothionein-like motif with similarity to metallothionein, but had a much longer sequence than metallothionein and contained repeated sequences of amino acids. Expression of MTC mRNA was sensitively induced by cadmium exposure at 0.3 mg/kg of dry food, a concentration at which toxic effects are not observed, but expression was not affected by gamma-ray exposure (an inducer of oxidative stress). These findings suggest that MTC is involved in cadmium-binding processes rather than in oxidative-stress responses. In conclusion, we suggest that gene expression of MTC may be a candidate biomarker for detecting low levels of cadmium contamination in soil.

• 出版日期2010-5