Publication Abstract

Oxidative stress response of European flounder (Platichthys flesus) to cadmium determined by a custom cDNA microarray

D.L. Sheader, T.D.Williams, B.P.Lyons and J.K. Chipman

The monitoring of the impact of chemical pollutants upon marine eco-systems commonly employs a multi-biomarker approach. Genomics, using cDNA microarrays, allows for a more comprehensive view of how an organism is responding to an exposure compared to the traditional approach. Differentially expressed mRNAs were isolated from livers of European flounder exposed to 2mg/kg (body weight) cadmium (Cd) and 5mg/kg benzo[a]pyrene (B(a)P), by means of suppressive, subtractive hybridisation. A clone set containing a total of 284 different potentially differentially expressed mRNAs was produced, of which 84 could be tentatively identified. These were combined with clones isolated by degenerate PCR to produce a small-scale custom microarray containing 497 distinct probes. These included probes corresponding to classical biomarkers and other genes known to respond to contaminant exposure. Subsequent array experiments detected up-regulation of 4 genes reflecting potential oxidative stress in Cd exposed flounder while combination exposure to both Cd and B(a)P showed changes in gene expression potentially associated with an increase in cell proliferation. The array experiments demonstrated the ability of this approach to investigate the effect of simultaneous exposure to mixtures of contaminants and highlight a number of candidate genes for further analysis as potential novel biomarkers.

Reference:

D.L. Sheader, T.D.Williams, B.P.Lyons and J.K. Chipman (2006) Oxidative stress response of European flounder (Platichthys flesus) to cadmium determined by a custom cDNA microarray. Marine Environmental Research, 62(1): 33-44