Genetically
modifying animals has come a long way, from selectively breeding dogs to our
heart's desire to adding green fluorescent protein (GFP) genes into zebrafish
embryos to produce fish that glow green while swimming around. Advances in
genetic modification have been astounding and the transition into labs has
given us more control over how certain genes are expressed and where they are
located in the genome. Ever since Watson and Crick (and let us not forget
Rosalind Franklin) discovered the structure of DNA in 1953, the field of
genetics has been growing in science. The breakthrough of completing the human
genome project in 2003 was yet another great step in the development of genetics.
Such advances in this field have led to the development of biotechnology, or
the use of organisms and living systems to make beneficial products or to
further our understanding of the life.
Science
has given us the chance to manipulate life for either the better, or for the
worse. Manipulation of genes has gone so far as genetically modifying goats to
produce human lysozyme in their milk for the treatment of intestinal problems
(both human and goat) by introducing the human lysozyme gene into goat embryos.
Work with cloning, while not yet perfected, has made major discoveries in the
process of how to clone our favorite family companions. Adding specific genes
to zebrafish results in fish that glow red, green, yellow, blue, or even purple
under certain light (which I have to say is quite fascinating to see). However,
companies also produce mice that have all sorts of diseases from Alzheimer's
disease, NSE-p25 mice, to mice that just drop dead from heart failure, 11BHSD2
mice, for research labs. The question then becomes, are these manipulations
morally acceptable? Everyone has their own opinion but as Emily Anthes, author
of Frankenstein's Cat:
Cuddling Up to Biotech's Brave New Beasts, puts it, "studying these
creatures yields valuable insight into human disease" (Anthes p.8-9) and
these studies could even provide insight into how to help these animals fight
disease. As for the glowing fish, GloFish, I have to agree with Anthes in
that as long as the new genes are not causing any harm to these animals, then there
is no cause for concern. In fact, there is less harm caused by many of these genetic laboratory changes than the harm caused by the selective breeding of dogs. Years of
inbreeding and selecting for certain traits have resulted in dogs like the English
bulldog that suffers from sleep apnea because its snout is so short. Its
breathing difficulties result in "trouble regulating [its] own body
temperature" (Anthes p. 29) and even heart or respiratory failure.
Ultimately, manipulation
of genes certainly has both positives and negatives, but we cannot forget the
benefits. Recent studies have observed naked mole rats and their curious
resistance to cancer. Vera Gorbunova and Andrei Seluanov of the University of
Rochester have discovered that naked mole rats from East Africa have the
strange ability to fight off cancer when injected with viruses that normally
trigger cancer in mouse cells. What causes this protection? A chain-shaped
molecule by the name of hyaluronan that prevents cancer cells from multiplying
out of control. Naked mole rat cells actually grow at a third the density that
mouse cells do because of this hyaluronan molecule. Hyaluronan, also found in
the stretchy gel that holds human cells together, actually sends signals into cells through
the CD44 receptor that instructs cells to change their direction of growth, or
even to start multiplying. These naked mole rats have high levels of this
molecule, but it is five times as long! Experiments in which enzymes destroyed
this hyaluronan or experiments that shut down the hyaluronan producing gene resulted in cells that multiplied
drastically. Such results show that this molecule helps the naked mole rats
fight cancer, but they did not evolve in this way to fight cancer originally.
Naked mole rats need to wiggle through underground tunnels, and stretchy skin, as a result of the long hyaluronan, helps them do just that. This necessary adaptation also fortunately prevented these mammals from developing cancer.
Looking into the
future, these findings can have major implications on a cure for cancer.
Further research must be done to see if this has the potential to be a cure, but it will not be the only cure if so. Research must first be done on animals that do not have this long of
hyaluronan, such as mice. Mice, as mentioned earlier, have been bred for all
kinds of diseases, but this time they will be used to see if this long form of
hyaluronan will prevent the growth of tumors. Using these mice to observe the
effects of long hyaluronan is a way to genetically engineer so that we can
better understand. Looking at the effects on an organism that normally does not
have this gene can help us determine how it would affect a human.
Anthes argues that
using an animal to test the effects of genes is morally acceptable if some
benefit can come from it. Doing this research can improve both the lives of
humans and even mice by reducing the risk of cancer. This research is certainly
justified and may potentially result in a new way to treat
in the field of
medicine.Sources:
Anthes, Emily. Frankenstein's Cat: Cuddling Up to Biotech's Brave New Beasts. , 2013. Print.
Zimmer, Carl. "A Homely Rodent May Hold Cancer-Fighting Clues". New York Times. June 19, 2013.
<http://www.nytimes.com/2013/06/19/science/a-homely-rodent-may-hold-cancer-fighting-clues.html>
No comments:
Post a Comment