Liver transcript expression patterns in the sparid striped seabream (Lithognathus mormyrus) upon exposure to cadmium. Lithognathus mormyrus

Changes in hepatic gene expression profiles upon exposures to cadmium applied by feeding or intra-peritoneal injections were identified in the striped sea bream (Lithognathus mormyrus) using cDNA microarray platform. Two groups of four fish were exposed to fed and injected CdCl2, respectively. Additional eight untreated fish were used as a reference group, pooled into 4 hepatic RNA preparations. The isolated hepatic mRNAs were hybridized, after conversion to labeled cDNAs, onto the microarray followed by slide scanning, imaging and analysis. Four parameters: M, meanA, P-value and B were calculated for each unique spot, for both cadmium-fed vs. reference fish (sample1) and cadmium-injected vs. reference fish (sample2). These parameters enable evaluation of hybridization intensity as well as statistical testing of differential expression. Keywords: Response to exposure to cadmium Overall design: Four biological replicate hybridizations were designed, each composed of labeled hepatic cDNAs of three individual fish, each taken from the two experimental conditions and the reference, respectively. The three cDNAs included in each biological replicate, were dual-hybridized in all three possible alternatives, ending with 12 slides. The two dyes were swaped for each pair of biological replicates to reduce putative dye effects. Graphic presentation of the hybridization scheme is provided as supplementary file.