Hepatic gene profile analysis for chronic exposure of clothianidin in early life stage sockeye salmon (Oncorhynchus nerka)

This study investigated the effects of the neonicotinoid insecticide clothianidin on hepatic gene expression in juvenile sockeye salmon. Four genetically distinct pairs of wild sockeye salmon were collected and fertilized in clean water, and were subsequently exposed to 0.15, 1.5, 15, 150 μg/L clothianidin from 1 hour post-fertilization through to the swim-up fry developmental stage. Individual swim-up fry livers from all genetic crosses and each treatment were collected and various genes of interest were quantified using quantitative PCR. The genes of interest evaluated in this study were estrogen receptor alpha and beta 2, cytochrome P450 1A, suppressor of cytokine signaling 3, and glucocorticoid receptor 2. The glucocorticoid receptor 2 showed a significant 4-fold downregulation at 150 μg/L compared to the control treated fish (p