Development and characterization of cell lines from heart, liver, spleen and head kidney of sea perch Lateolabrax japonicus

Abstract

Five cell lines (LJHK, LJS, LJL, LJH‐1 and LJH‐2) were established from the head kidney, spleen, liver and heart of sea perch Lateolabrax japonicus. The cell lines LJHK, LJS, LJL, LJH‐1 and LJH‐2 were subcultured 46, 32, 32, 36 and 34 times in minimum essential medium (MEM) supplemented with foetal bovine serum (FBS), sea perch serum and 10 ng ml−1 basic fibroblast growth factor (bFGF). Morphology of primary cultures and subcultures of the five cell lines were observed continuously by microscopy. The suitable temperature for growth was 18 to 30° C for all of these cell lines with the optimum growth at 24° C and a reduced growth rate <18° C. The optimum concentration of FBS was found to be 10% and addition of bFGF to the medium significantly increased the growth rate of the cells. The doubling time of LJS, LJH‐1, LJL, LJH‐2 and LJHK cells was determined to be 52·7, 54·9, 57, 58·7 and 66 h at a plating density of 1 × 105 cells ml−1 at 24° C, respectively. Chromosome analysis revealed that 42, 48, 38, 43 and 45% cells maintained normal diploid chromosome number (48) in the LJH‐1, LJH‐2, LJHK, LJL and LJS cell lines, respectively. The LJHK cells were successfully transfected with green fluorescent protein (GFP) reporter plasmids and the expression of GFP gene in the cells indicated the possible utility of the cells in gene expression studies. Furthermore, treatment of the LJHK cells with lipopolysaccharide led to increased expression of IL‐1β, demonstrating that LJHK cells might be a valuable tool for studying the expression and function of immunomodulatory gene in fishes.