Development and characterization of a cell line from the caudal fin of Schizothorax niger (Heckel, 1838) for in vitro toxicity testing.

Here, we successfully grew the SNCF (Schizothorax niger caudal fin) cell line from the caudal fin explants of S. niger, an important cold-water fish of the Himalayas. The cells were successfully grown up to 22 passages by planting explant tissues in DMEM medium supplemented with FBS. We observed optimal cell growth at a concentration of 18% FBS. We observed the steady generation of cells from explants from days 2 to 5 of seeding, and obtained a complete monolayer at days 7-10. We tested various temperatures, including 10 °C, 13 °C, 16 °C, 19 °C, 22 °C, 25 °C, and 28 °C, and found that 22 °C was the optimal temperature for cell growth. We examined the response to various doses of epidermal growth factor (EGF) and fibroblast growth factor (FGF) (0, 2, 4, 6, 8, and 10 ng/mL) on cell colony growth at an optimal temperature of 22 °C. We characterized the cell line using karyotyping at the 14th and 20th passages. The cell line showed epithelial cell-like growth by morphology, which was confirmed by immunotyping. We further used the cell line to study the impact of three pesticides (chlorpyrifos, dimethoate, and endosulfan), and a fungicide (mancozeb) and bacterial extracellular product (ECP). The DAPI stain assay and MTT assay confirmed the pesticides toxic effects on the cells, revealing disintegration of the cell nuclei by the formation of micronuclei and LC₅₀ concentrations. ECP treatment showed disruption of the monolayer within 0-36 hrs.