Most people shy away from the idea of creating
genetically modified organisms, whether they are used for research or released
into the wild. Some are concerned about the overall welfare of the animals,
while others believe that scientists are trying to ‘play God’. They are
uncomfortable of man’s tinkering with nature as it has evolved to be, and are
convinced that accepting genetically modified animals into society will
inevitably lead to the even more
controversial modification of the human genome.
However, not all genetically altered
organisms are a threat to humanity and the natural world. A recent National
Geographic article featured the genetic engineering product of scientists at
the U.K.’s University of Exeter. They have recently engineered zebrafish that fluoresce
when in the presence of endocrine disruptors, or pollutants, in freshwater.
The
fish were injected with genetic elements that specifically glowed where the
toxins were affecting their bodies. Then they were exposed to common freshwater
pollutants that are known to cause decreased fertility and increased cases of
cancer in humans (Handwerk, 2012). The detrimental chemicals that the
scientists used in their experiment are ones commonly found in contraceptive pills,
plastics, paint, and industrial detergents (Handwerk, 2012). The experimenters were
able to determine varying thresholds at which the pollutants affected the fish.
By observing the mechanics of endocrine disruptors on zebrafish organs under a special microscope, scientists were able to gain a better understanding of how the
same pollutants affect human health. Previously, the chemicals used in the
experiment were thought to affect the liver, testes, and ovaries in humans. The
Exeter study confirmed that the chemicals were also detrimental to the brain
and heart.
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| Zebrafish fluorescing in areas affected by harmful chemicals |
Modern fluorescence technology is
limited because it only works on young fish. In order to observe
fluorescing tissues and organs, their skin must be partially transparent. The
next goal in this technology is to create a strain of zebrafish that lack skin
pigmentation, allowing research to be applicable to adult zebrafish.
In Emily Anthes’ book Frankenstein’s Cat, a pet company called
GloFish is introduced. As the name suggests, GloFish sells zebrafish that fluoresce
vibrant colors underneath a black light. The creators of GloFish, Alan Blake
and Richard Crockett, borrowed a gene from a crystal jellyfish and placed it in
zebrafish embryos. The gene, named GFP for green fluorescent protein, is
responsible for the jellyfish’s neon green hue. Sure enough, it took the same
effect on zebrafish as well. Soon after this discovery, Black and Crockett
borrowed more genes from a sea anemone to expand the spectrum of their GloFish
selection.
The zebrafish that Blake and Crockett
used to begin their company came from the university laboratory of Zhiyuan
Gong. The GloFish inspired Gong to use GFP to create a strain of fish that
would fluoresce in the presence of- you guessed it- endocrine disruptors! Gong’s
experiments sparked a wave of research that utilized fluorescence in the
detection of harmful chemicals.
The results of this type of research benefits
both humans and freshwater organisms.
It exemplifies the good that genetic engineering can bring to the world,
without placing humans as the sole benefactors of the research.
References:
Anthes, Emily. "Go
Fish." Frankenstein's Cat: Cuddling Up To Biotech's Brave New Beasts. 1st
ed. New York: Scientific American, 2013. 13-32. Print.
Handwerk, Brain. "Daily Nature
and Science News and Headlines | National Geographic News." National
Geographic. National Geographic Society, 23 Apr. 2012. Web. 11 Oct. 2013.
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