Development and characterization of two new cell lines from milkfish (Chanos chanos) and grouper (Epinephelus coioides) for virus isolation.

Two new cell lines, SIMH and SIGE, were derived from the heart of milkfish (Chanos chanos), a euryhaline teleost, and from the eye of grouper (Epinephelus coioides), respectively. These cell lines were maintained in Leibovitz's L-15 supplemented with 20% fetal bovine serum (FBS). The SIMH cell line was subcultured more than 50 times over a period of 210 days and SIGE cell line has been subcultured 100 times over a period of 1 1/2 years. The SIMH cell line consists predominantly of fibroblastic-like cells. The SIGE cell line consists predominantly of epithelial cells. Both the cell lines were able to grow at temperatures between 25 and 32 degrees C with an optimum temperature of 28 degrees C. The growth rate of these cells increased as the proportion of FBS increased from 2% to 20% at 28 degrees C with optimum growth at the concentrations of 15% or 20% FBS. Seven marine fish viruses were tested to determine the susceptibility of these cell lines. The SIGE cell line was found to be susceptible to nodavirus, MABV NC-1 and Y6, and the infection was confirmed by cytopathic effect (CPE) and reverse transcriptase-polymerase chain reaction. When these cells were transfected with pEGFP-N1 vector DNA, significant fluorescent signals were observed, suggesting that these cell lines can be a useful tool for transgenic and genetic manipulation studies. Further, these cell lines are characterized by immunocytochemistry using confocal laser scanning microscopy (CFLSM).