Transformation of Fish Cells and Embryos

Fish are the largest group of vertebrates. They have diverse features to adapt to a wide variety of environments, which make them excellent models for studies in various areas, including molecular and cellular biology (1 ,2 ). Small freshwater species, such as medaka (Oryzias latipes ) and zebrafish (Brachydanio rerio ) are being studied in a growing number of laboratories because of their advantages as experimental animals (2 ,3 ). The procedures for the preparation and maintenance of fish cell cultures do not differ from those of higher vertebrates. In general, fish cells grow in the same medium as mammalian cells and can be preserved by standard methods for freezing. A specific feature of fish cells is that they generally proliferate over a wide range of temperatures, and the optimal growth temperature reflects the environment that each species inhabits (4 ,5 ). In addition, fish cells are thought to be naturally immortal. Even cells derived from nonneoplastic tissues can grow continuously (6 –8 ).