The gene expression changes in hydra exposed to ZnO nanoparticles

Abstract

ZnO nanoparticles have been used in many fields like plastics, ceramics, rubber, lubricants, paints, ointments, adhesives, sealants, pigments and foods (source of Zn nutrient). The potential risks and effects on the human health were reported when it exposed through inhalation and dermal contact. This study aimed to investigate the biological effects and risks of ZnO nanoparticles and used a cnidarian, hydra as an experimental animal because Hydra has relatively short life cycle and is maintained easily in laboratory. We carried out acute toxicity test for 20 nm ZnO and 100 nm ZnO and did microarray experiment using hydra exposed to 20 nm ZnO and 100 nm ZnO to examine the gene expression changes by ZnO nanoparticles. As a results, the LC50 for 72 hours was 8.7 mg/L in 20 nm ZnO exposure and 14.9 mg/L in 100 nm ZnO exposure. For the microarray experiment we exposed hydra to 20 nm ZnO and 100 nm ZnO as the concentration of 1/50 of LC50 for 12 hours and hybridized those RNAs extracted from the exposed groups with that of control group on the hydra cDNA chips including 17639 genes. As the results, 137 genes expressions were induced and 106 genes were reduced over 10 fold by 20 nm ZnO exposure. Among them the expression of multidrug-Resistance like Protein 1 CG6214-PM gene increased over 100-fold. In 100 nm ZnO exposure, the expressions of 137 genes were induced over 10 fold and 106 genes w