Fig. S1.

Optimization of transient transfection of tilapia OmB cells. (A) Phase-contrast micrograph showing OmB cells at 80% confluency. (Scale bar, 200 µM.) (B) Fluorescence micrograph showing OmB cells transiently transfected with eGFP plasmid (Addgene) and counterstained with NucBlue Live ReadyProbes Reagent (Thermo Fisher Scientific) (Scale bar, 25 µM.) (C) In addition to the eGFP reporter, luciferase reporter assays indicate that constitutive reporter gene activity (Firefly luciferase driven only by the minimal promoter) is highest when OmB cells are transfected at 80% confluency and luciferase activity is measured 96 h after transfection. All cells were cultured in isosmotic medium (315 mOsmol/kg) for these experiments; data represent means ± SD. RLU, relative luciferase activity units.