Establishment, characterization and myogenic capacity of a muscle-derived cell line from Korean rockfish (Sebastes schlegelii).

A cell line from Korean rockfish, Sebastes schlegelii muscle was successfully established and characterized. Primary cultures were initiated by enzymatic digestion and maintained in Leibovitz-15 (L-15) medium supplemented with 20% fetal bovine serum (FBS). The cells were continuously sub-cultured and maintained in L-15 with 10% FBS, 10 ng/mL fibroblast growth factor-2 (bFGF), and 1% antibiotics (penicillin/streptomycin and antibiotic/antimycotic solution) for more than 60 passages over 10 months, and named Korean rockfish muscle Sebastes schlegelii-1 (KRMSS-1) cell line. Under experimental conditions, best growth was achieved at 24 °C with 20% FBS concentration and 10 ng/mL bFGF addition. Cryopreservation using 5% dimethyl sulfoxide (DMSO) resulted in an 85-90% recovery rate after three months of freezing. Amplification of a CO1 fragment of the expected size provided supporting evidence for the rockfish origin of the KRMSS-1 cell line. Myogenic capacity was checked following serum reduction to 2% horse serum, resulting in myocyte alignment and cell fusion. During progression of the differentiation process, myosin heavy chain (MyHC) immunofluorescence staining revealed positive fluorescence distributed along elongated and enlarged cytoplasmic regions, indicating myogenic capacity. Differentiation success was further confirmed by increased protein expression of myogenin, desmin, and MyHC. Activation of intracellular PI3K/Akt/mTor and MEK/ERK pathways suggest a potential association between pathway activation and the differentiation process. Lastly, an increased proportion of cells in the G0/G1 phase at day 3 post-induction confirmed cell-cycle withdrawal. Collectively, this study established a new teleost muscle cell line with myogenic potential, providing a new model for muscle cell physiology research and for future aquaculture biotechnology applications.