Establishment and characterization of two cell lines from bluefin trevally Caranx melampygus

Bluefin trevally Caranx melampygus Cuvier is a popular game fish and highly valued sea food with potential importance for aquaculture. To help establish this marine animal as an important aquacultural species in Hawaii and the Pacific and develop in vitro cell culture systems for long-term management and control of potential viral diseases 2 cell lines were established from body muscle (bluefin trevally muscles, BTMS) and fins (bluefin trevally fins, BTF). Primary culture of these cells was conducted at 25 degrees C using L-15 medium supplemented with 20% fetal bovine serum and various antibiotics. These cells have been serially subcultured 37 to 41 times since their initiation in June 2002. Growth of the bluefin trevally cells was serum-dependent at the time of the experiments and their plating efficiencies ranged from 11 to 28.2%. Comparative analysis showed that these bluefin trevally cells grew equally well in the media L-15 (Leibovitz medium), RPMI 1640, M199 and MEM (minimum essential medium), which are commonly used for cell cultures derived from aquatic animals and mammalian species. Examination of the early passage cells stored at -196 degrees C revealed a large percent (nearly 98%) of cell viability following a 6 mo storage in liquid nitrogen. Karyotyping analysis indicated that these bluefin trevally derived cell lines remained diploid with a chromosome count of 48 at passage 7 and 12. These 2 cell lines shared a same pattern of viral susceptibility and they were sensitive to infectious hematopoietic necrosis virus (IHNV), infectious pancreatic necrosis (IPN), spring viremia carp virus (SVCV), viral hemorrhagic septicemia virus (VHSV), and snakehead rhabdovirus (SHRV) but refractory to channel catfish virus (CCV) infection. These newly established cell lines are currently being used to facilitate the diagnosis of viral disease affecting marine fish aquaculture in Hawaii, and will be available for future isolation and study of bluefin trevally fish viruses.