No Need to Worry: Fluorescent Tadpoles on Patrol

Fluorescent tadpole in the presence of chemical contaminants

       Due to Lemkine's and Demeneix's lastest work in genetic modification, there is a new superhero in town: fluorescent tadpoles. With the ability to combat villains such as plasticizers, resins, and fumigants, these pint-size heroes measure up to Marvel's very own Thor and Captain America. In a recent article published in Scientific American titled "Unhealthy Glow: Fluorescent Tadpoles Expose Chemical Contamination", Erica Gies discusses a novel use of green fluorescent protein (GFP) to detect pollutants.

        GFP, as a bioluminescent protein derived from the jellyfish, Aequorea victoria, absorbs ultraviolet light and re-emits green light without any accompanying factors. Watchfrog, a Pharmaceutical and Environmental company, isolated the gene for green fluorescent protein and introduced it into the genome of Xenopus tadpoles. Specifically, the GFP gene was fused to genes responsible for thyroid functioning whose gene expression occurs in the presence of thyroid hormones. It is argued that chemical pollutants such as "insecticides, herbicides, fumigants, fungicides, detergents, resins and plasticizers" mimic the hormones, causing expression of GFP and subsequent fluorescence. To put it simply, these transgenic tadpoles glow green when exposed to chemical pollutants, protecting society from entering harmful waters. With a high demand to monitor unhealthy contaminants, the U.S. Environmental Protection Agency (EPA) has currently put these tadpoles to use. In cooperation with the EPA, Watchfrog has teamed up with Pathfinders, an EPA program, to further develop a miniscule device known as the FrogBox that records pollutant levels over time within the transgenic swimmer.

       In Frankenstein's Cat, Cudding up to Biotech's Brave New Beasts, Emily Anthes comments on the potential uses of green fluorescent protein as a means to visualize the expression of genomic DNA when coupled to specific sequences. She states, "GFP has become a valuable tool for geneticists. Researchers testing a new method of genetic modification can practice with GFP, splicing the gene into an organism's genome. If the animal lights up, it's obvious the procedure worked" (16). This fusion of foreign DNA with a host cell's genome is called a  transgene and characterizes transgenic organisms. Examples provided by Anthes include Atlantic salmon with a transgene for growth hormone created by AquaBounty, and goldfish with the introduction of GFP known as Glofish. As parallels to the examples, the fluorescent tadpoles have been received with hostility by the scientific community due to the harmful effects the contaminants have on the living detectors. Specifically, the pollutants disrupt the endocrine system of the tadpoles, affecting metamorphosis. At the same time, the transgenic organisms serve a greater purpose in protecting humans from such harmful contaminants.

        Anthes comments on these conflicting views referring to society as a "troubled middle" in which we understand the importance of using animals for medical research but at the same time do not support animal cruelty. To elaborate, Anthes mentions that "71 percent of Americans said that animals deserved some protection from harm and exploitation, an additional 25 percent said that animals should have the same rights as people.....and yet 64 percent of all respondents accepted the practice of using animals in medical research" (168). With advancements in biotechnology, this conflict between ethics and scientific ability will only become more and more prevalent. Is it justifiable to "play God" simply for aesthetic purposes? Is it moral to cause animals discomfort for the good of humanity as a whole? Such questions do not and will not have straightforward answers. The solution lies in evaluating each dilemma case by case. Anthes best summaries, "We'll have to carefully evaluate each application on its own terms, trying to balance what's in the best interest of the individual animal with what's good for species as a whole, for humanity and for the world that we all share"  (169).

References:

Gies, Erica. Unhealthy Glow: Fluorescent Tadpoles Expose Chemical Contamination. Scientific American, 7 Feb. 2013. Web. 6 Oct. 2013.
 http://www.scientificamerican.com/article.cfm?id=transgenic-tadpole-glows-to-reveal-chemical-contamination

Anthes, Emily. Frankenstein's Cat Cuddling Up to Biotech's Brave New Beasts. New York: Scientific American/Farrar, Straus and Giroux. 2013