Dose-responsive transcriptomic profiles in red drum (Sciaenops ocellatus) larvae exposed to Deepwater Horizon oil

Purpose:To help identify molecular mechanisms and pathways potentially involved in the developmental toxicity for estuary fish exposed to different concentrations of Deepwater Horizon (DWH) oil, transcriptomic profiles in red drum (Sciaenops ocellatus) embryos exposed to different DWH oils (source/mass and artificially weathered oil) were evaluated using High Throughput Sequencing (HTS). Methods:Total mRNA profiles of 48 hpf red drum larvae after slick (1.25%, 2.5%, and 5%) and source/mass oil (0.135%, 0.27% and 0.54%) exposure were generated by deep sequencing, in triplicate, using Illumina NextSEQ v2. Results:To determine the potential biological impact of oil exposure at system level, a gene ontology (GO) term analysis on biological processes (BPs) was conducted by analyzing the DEGs using DAVID. After exposure to source oil, the top enriched biological processes were terms associated with oxidation-reduction process, metabolic process (e.g. steroid), and organism development. Similar biological processes were also among the most significant biological processes by slick oil exposure. Among the top biological process list a significant number of nervous system related terms were highly enriched by both source and slick oil exposure, including midbrain development, motor neuron axon guidance, nervous system development, eye development, neuron development, neuron differentiation etc. Overall design: Total mRNA profiles of 48hpf red drum larvae after slick and source oil exposure were generated by deep sequencing, in triplicate, using Illumina NextSeq 500.