Transgenic Fish: Researches and Applications

The gene transfer technology applied in commercially important aquatic animals is to enhance the quality or to improve the genetic characters of aquaculture broodstocks. The anti-freezing transgenic salmon and the fast-growing transgenic fish and shellfish have been reported and consider as the most successful cases until now. It highlights a new access to the modification of food fish and shellfish. However, the issues of genetically modified organisms (GMO) are still controversial. Food safety and ecological impacts are the major concerns before GMO are put in the market. For research purpose, zebrafish (Danio rerio) and medaka (Oryzias latipes) have become the most used model organisms since they are primitive vertebrates yet have many advantages over the other. Transgenes is, in vivo transient assay, mutagenesis and knock-down translation of zebrafish embryos are the most effective ways to map expression profiles, to dissect the regulatory cis-elements and to identify the gene functions of vertebral genes. Germ-line transmission is much more easily accessible. Transgenic line carrying a specific tissue tagged by green fluorescent protein (GFP) live marker become a powerful tool to study developmental biology because they enable to recapitulate the expression of endogenous genes. Furthermore, the transparent embryos are available for observation and tracing dynamic expression of a specific gene during embryogenesis. Transgenic fish can also serve as a simple animal model to study human diseases because some zebrafish mutants can faithfully phenocopy human diseases. For application purpose, GFP lines are potentially applied as biosensors for detecting the environmental pollutants. Interestingly, new pet fish species that glows colorfully in the dark can be achieved by transferring fluorescent protein genes. These advantages make the transgenic model fish apt for modern biomedical researches and applications as new materials.