Transgenic Fish Model for Mutagenicity Testing

The goal is to develop an in vivo mutagenicity assay based on transgenic fish. The transgeneto be incorporated is a lambda phage shuttle vector with a lac I target gene that has demonstratedsensitivity to mutagens. After exposing fish to suspected mutagens, the vector is rescued from fishgenomic DNA with lambda phage packaging extracts. Subsequent infection of E. coli, allows mutationsto be visually scored by blue/white color selection of plaques, formed on an E. coli lawn. Small speciesof fish have been used extensively in evaluating carcinogenicity of test compounds, and have shownthemselves to be useful in identifying human carcinogens prior to rodent bioassay. Therefore, afish-based mutagenicity assay will allow a more in-depth evaluation of suspected mutagens by extendingmultiple species testing. However, unlike current rodent bioassays, a fish-based mutagenicity assay willalso allow in-depth evaluation of mutagens contaminating aquatic ecosystems and open new avenuesof testing compounds prior to release into the environment. In addition, the ability to visualize embryonicdevelopment combined with the ready supply of large numbers of fertilized eggs will allow this assayto be adapted to analyzing mutagenic-potential of teratogens. During phase I the feasibility ofconstructing transgenic fish will be explored; in phase II, the system will undergo further developmentby producing high copy fish and initial testing of mutagens.