Photomicrograph of injecting
a zebrafish embryo

Making of a transgenic fish. Pollution responsive reporter genes are microinjected into one-celled fish embryos shortly after fertilization. The functional gene is incorporated into the genome of a small portion of the injected fish, and the degree to which it mimics native gene expression is determined.

Representation of our transgenic fish sentinel for biological monitoring. Transgenic zebrafish with pollution responsive DNA elements are placed in a body of water. The contaminants bioconcentrate 1,000- to 100,000-fold in the tissues of the fish, activating the response elements (RE) that induce the production of luciferase. This assay does not require killing the fish and allows for repeated analysis of the same site with the same fish.

Project Summary:
Municipal drinking water systems are potential targets for terrorists and are vulnerable to both intentional and accidental contamination.  Intentional contamination could result from direct introduction of a toxic chemical into a drinking water system, or intentional destruction of a structure, that causes chemical contamination of the system.

The distribution systems for drinking water are the most vulnerable and deliver their product directly to numerous homes and workplaces. This transgenic sentinel can monitor these vulnerable systems by detecting biologically significant doses of innumerable different chemicals.

In our laboratory we have assayed 18 potential environmental chemical contaminants, including biological warfare agents such as parathion and paraoxon (chemical relatives of sarin). We will generate lines of transgenic zebrafish biomonitors by introducing an easily assayable reporter gene under the control of pollution responsive DNA elements.  The final product of this project will be a sentinel for biological monitoring of environmental pollution capable of recognizing toxic chemicals within a complex environmental mixture, using an easily assayable reporter gene in live fish.