“…An ideal D. rerio in vitro cell system, however, susceptible to various fish viruses and effective in exogenous gene expression, has not been available, although c. 20 D. rerio cell lines have been developed (Xing et al, 2009) and six of them were commercially available, ZF4, PA C2, ZEM2, ZFL, AB.9 and SJD.1 (ATCC; www.atcc.com). Only ZF4 cells, which were cytogenetically heteroploid, had been reported to be susceptible to NNV and SVCV (Chen et al, 2015;Li et al, 2015).…”