Copper nanoparticles (Cu-NPs) are components in numerous commercial products, but little is known about the mechanisms of their toxicity to marine fish. Here, we investigated physiology, transcriptome and proteome in Epinephelus coioides after exposure to Cu as Cu-NPs or copper sulfate (CuSO4). Aggregation, oxidation and dissolution of Cu-NPs occurred after suspension in seawater within 24 h. Cu-NPs had similar types of the histology and hematological effects as CuSO4 on E. coioides, but toxicity of Cu-NPs seems more severe than that of CuSO4. Venn diagram analyses revealed 1428 and 2239 genes with significantly altered regulation in, respectively, CuSO4 and Cu-NPs treatments; of these, 911 genes were common to both treatments. A total of 354 and 140 proteins with significantly altered regulation were identified in, respectively, CuSO4 and Cu-NPs treatments; of these, 75 proteins were common to both treatments. A total of 11,417 transcripts and 3210 proteins were assigned to gene ontology terms, clusters of orthologous groups and Kyoto encyclopedia of genes and genomes. Correlation analysis of gene and protein expressions revealed that 21 differentially expressed proteins had their regulation changed in the same direction in both Cu-NPs and CuSO4 treatments. Those genes and proteins could be used as targets for subsequent analysis, regardless of the Cu form. Among those proteins, one of the most notable changes was in proteins related to lipid transport and metabolism. This study provides an enhanced understanding of E. coioides responses to Cu-NPs or CuSO4.
Keywords: Epinephelus coioides; Transcriptome; copper nanoparticles; copper sulfate; proteome.