Development of a cell line from the gill of turbot (Scophthalmus maximus) and its application in the study of Edwardsiella piscida infection

• A new cell line from the gill of Scophthalmus maximus was established. • The fundamental characteristics of the cell line were systematically analyzed. • The cell line is an ideal model for studying the interaction of host and E. piscicida . In this study, we established and characterized a continuous cell line derived from the gill tissue of turbot ( Scophthalmus maximus ) and assessed its applicability in studying the gill's function as a mucosal immune barrier. This cell line, designated SMG, has been successfully subcultured for up to 70 passages. The SMG cells exhibited robust growth in DMEM medium supplemented with 20 % FBS at 24 °C. Karyotype analysis revealed that the modal chromosome number of SMG cells was 44. Amplification of the 18S rRNA confirmed the turbot origin of the SMG cells. The cell line was transfected with a pEGFP-N1 plasmid and FAM labeled siRNA, resulting in high transfection efficiency and successful expression of the transfection reporter gene and FAM fluorescence signals 48 h post-transfection. Edwardsiella piscicida replicated in SMG cells at low concentrations without altering the morphology of the cells in the early stages of infection. These findings indicate the potential utilization of SMG cells in studying gene function and antimicrobial responses. This research provides a foundation for future studies on the immune barrier of gill mucosa in marine species.