Gene expression in Gammarus pulex in response to chlorantraniliprole exposure
Pesticides are important agricultural stressors for freshwaters, but the physiological mechanisms induced by pesticide exposure are largely unknown for most aquatic non-target organisms. The insecticide chlorantraniliprole, an agonist of the ryanodine receptor, has been reported to be highly selective for target pest species, which comprises representatives of the order Lepidoptera (butterflies). Using RNA sequencing data, we quantified the insecticide effect on the gene expression profiles of the amphipods Gammarus pulex and other freshwater invertebrates. Organisms were exposed for 48 hours to three different concentrations of chlorantraniliprole. Further, the effect of biotic interaction between the two shredder G. pulex and L. basale on the insecticide induced gene expression profiles was tested. RNA extracts were pooled from up to 3 amphipods to one library, irrespective of their sexe. Per concentration, 6 libraries (replicates) were sequenced on an Illumina Novaseq 6000, resulting in 24 RNA-seq libraries (6 x control, 6 x low concentration treatment, 6 x medium concentration treatment, 6 x high concentration treatment). Each of the insecticide treatment levels comprised 3 replicates where only G. pulex was present as shredder species, and 3 replicates where G. pulex and the competing shredder L. basale was present. In contrast to the exposed insect species, we detected only a weak transcriptional response in the amphipod G. pulex.