Ref ID : 6723
Dana F. Simon, Patrick Descombes, William Zerges, and Kevin J. Wilkinson; Global expression profiling of Chlamydomonas reinhardtii exposed to trace levels of free Cadmium. Environmental Toxicology & Chemistry 27(8):1668-1675, 2008
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In the natural environment, cadimum is often found as a trace contaminant. Due to the complexity of Cd speciation and the heterogeneity of natural systems and processes, it is often difficult to determine clear relationships between analytical measurements of Cd and its induced biological response. Measurements of gene induction can be used to identify molecular mechanisms underlying toxicity and to quantify sublethal responses to trace contaminants. In the present paper, genes that could be involved in the tolerance of Cd to green algae were examined using two global transcriptome profiling strategies. Microarray and differential display techniques were used for a global transcriptome analysis of Chlamydomonas reinhardtii exposed to micromolar and lower Cd2+ concentrations for a short period (2 hr). Real-time quantitative polymerase chain reaction analysis confirmed that a small set of 10 genes was differentially expressed in response to trace Cd2+ exposures ranging from 7.8 nM to 9.0 µM. Since induction was only oberved for a few genes, none of which are known to function in a general stress response, it was likely the result of relevant responses to Cd exposure. The identified genes are discussed with respect to their possible involvement in Cd tolerance and to their future use as biomarkers for monitoring Cd bioavailability in natural soils and waters.