A new embryonic cell line YCE1 from large yellow croaker (Larimichthys crocea) and its susceptibility to large yellow croaker iridovirus

In order to develop in vitro culture models for the viral pathogens found in large yellow croaker (Larimichthys crocea), a new cell line derived from L. crocea embryo, YCE1, was established and characterized. This cell line has been maintained in vitro for over 24 months, and subcultured for >80 times in a Leibovitz's L-15 medium supplemented with fetal bovine serum (FBS). The YCE1 cells, which were identified to be predominantly fibroblast-like by immunofluorescence, are able to form a monolayer at 15–37 °C, with an optimum growth temperature of 26 °C. In the chromosome analysis, the YCE1 cells exhibited to be highly heteroploid. The green fluorescence protein (GFP) reporter gene was successfully expressed in the YCE1 cells. In the susceptibility test with regard to large yellow croaker iridovirus (LYCIV) in the YCE1 cells, noticeable and stable cytopathic effects (CPEs) were found in a host-origin cell line for the first time. In addition, a special intracellular pattern of the immature viral particles contained in vesicular organelles was confirmed by transmission electron microscopy, suggesting that the YCE1 cell line could serve as a viable tool for the investigation of host-pathogen interaction of LYCIV and other related megalocytiviruses.