[Cold stress causes early apoptosis in caudal fin cells of Colossoma brachypomum].

CBT cell line developed from a warm-water fish Colossoma Brachypomum,was used to evaluate the effects of cold stress on fish cells. Cell viability was measured by Thiazolyl blue (MTT) method and cellular ultrastructure was examined under transmission electron microscope. Externalization of phosphatidylserine(PS) and mitochondrial membrane potential(MMP) were monitored with confocal laser scanning microscope. Results showed that cell viability and MMP decreased in a time-dependent manner, and the early events of apoptosis such as chromatin condensation, margination and PS externalization occurred, when the cells were exposed to 10 degrees C. It suggested that low temperature (10 degrees C) could induce apoptosis in Colossoma Brachypomum CBT cells.