Gene expression profile in zebrafish D. rerio exposed to metal oxidate nanoparticles

Metal oxide nanoparticles can exert adverse effects on humans and aquatic organisms. However, the toxic effects and mechanisms of MO-NPs are not clearly understood.We investigated the toxic effects and mechanisms of copper oxide, zinc oxide, and nickel oxide nanoparticles in Danio rerio using microarray analysis. After two weeks of acclimation, D. rerio were exposed to eight concentrations of each NP solution (ZnO: 1.0, 2.0, 4.0, 8.0, 16.0, 32.0, 64.0, and 128.0 mg/L; CuO: 0.0625, 0.125, 0.25, 0.5, 1.0, 2.0, 4.0, and 8.0 mg/L; NiO: 2.0, 4.0, 8.0, 16.0, 32.0, 64.0, 128.0, and 256.0 mg/L) with a day/night cycle of 16/8 h. Three biological replicates were used in each treatment and each replicate consisted of 10 individuals. D. rerio were exposed for 96 h without feeding. Survival rates were recorded each day and the median lethal concentration (LC50) was calculated using the probit method. The subsequent exposures for the microarray were performed using one-tenth of the LC50 for each NP solution (0.2 mg/L CuO, 4.8 mg/L ZnO, and 17.5 mg/L NiO). Ten D. rerio were sacrificed for each treatment, and the gills were pooled as a sample. Three biological replicates were used for each treatment.