ABSTRACT: Purpose: To help identify molecular regulatory mechanisms of developmental toxicity for fish exposed to Deepwater Horizon (DWH) oil, microRNA profiles in mahi-mahi (Coryphaena hippurus) larvae exposed to different DWH oils (source/mass and artificially weathered oil) were evaluated using High Throughput Sequencing (HTS). Methods: Total microRNA profiles of 48 hpf mahi-mah larvae after slick (0.5%, 1%, and 2%) and source/mass oil (0.125%, 0.25% and 5%) exposure were generated by deep sequencing, in triplicate, using Illumina NextSEQ v2. Results: Among over 100 significant DE miRNAs, DE miRNAs that were inversely correlated with target mRNAs after slick and source oil exposure were identfied. miR-34b, miR-181b, miR-23b, and miR-203a responsive to both slick and source oil exposure were further filtered to predict downstream biological functions. The target genes of these four miRNAs were involved AhR signaling, Cardiac β-adrenergic signaling, nNOS signaling in neurons, xenobiotic metabolism signaling, p53 signaling, cell cycle regulation, etc., as well as potential diseases including cardiovascular disease, neurological disease, developmental disorder, ophthalmic disease, metabolism disease, etc.
