Establishment and characterization of a muscle cell line from golden pompano (Trachinotus ovatus) and its application in viral susceptibility

A new cell line, golden pompano muscle (GPM), was developed and characterized from the muscle tissue of the golden pompano in this work. GPM cells were mostly fibroblast-like and proliferated well in Leibovitz's L-15 medium supplemented with fetal bovine serum (FBS) (concentration of 10% to 20%) at 28 °C. The cell line has been stably passed over 80 generations and has been successfully cryopreserved. Molecular characterization of cytochrome oxidase subunit I (COI) confirmed that the GPM cells used in this study were from the golden pompano. Chromosome analysis showed that the diploid chromosome number of GPM cells was 2 N = 48. The enhanced green fluorescent protein (EGFP) reporter gene was successfully expressed in the GPM cell line by liposome transfection technique, and the transfection efficiency of GPM cells was about 60%, which suggests that GPM cells are available for research on gene expression in vitro. Virus susceptibility assay showed that GPM cells were susceptible to red-spotted grouper nervous necrosis virus (RGNNV), evidenced by the occurrence of cytopathic effect (CPE) and the increased viral protein synthesis capacity. Furthermore, viral replication significantly increased the expression levels of interferon (IFN) related signaling molecules and pro-inflammatory cytokines in cells. Therefore, our work developed and characterized a new cell line from golden pompano muscle, which allowed for functional studies of genetic manipulation, viral pathogenesis, and the interactions of host and virus.