Mad science
Glow-in-the-dark cats? It may sound like science fiction, but they’ve been around for
years. Cabbages that produce scorpion poison? It’s been done. Oh, and the next time
you need a vaccine, the doctor might just give you a banana.
These and many other genetically modified organisms exist today because their DNA
has been altered and combined with other DNA to create an entirely new set of genes.
You may not realize it, but many of these genetically modified organisms are a part of
your daily life — and your daily diet. Today, 45 percent of U.S. corn and 85 percent of
U.S. soybeans are genetically engineered, and it’s estimated that 70 to 75 percent of
processed foods on grocery store shelves contain genetically engineered ingredients.
Here’s a look at the some of the weirdest genetically engineered plants and animals
already in existence — and many that are coming your way soon. (Text: Laura Moss)
Glow-in-the-dark cats
In 2007, South Korean scientists altered a cat’s DNA to make it glow in the dark and then
took that DNA and cloned other cats from it — creating a set of fluffy, fluorescent felines.
Here’s how they did it: The researchers took skin cells from Turkish Angora female cats
and used a virus to insert genetic instructions for making red fluorescent protein. Then
they put the gene-altered nuclei into the eggs for cloning, and the cloned embryos were
implanted back into the donor cats — making the cats the surrogate mothers for their
own clones.
What’s the point of creating a pet that doubles as a nightlight? Scientists say the ability to
engineer animals with fluorescent proteins will enable them to artificially create animals
with human genetic diseases.
Enviropig
The Enviropig, or “Frankenswine,” as critics call it, is a pig that’s been genetically altered
to better digest and process phosphorus. Pig manure is high in phytate, a form of
phosphorus, so when farmers use the manure as fertilizer, the chemical enters the
watershed and causes algae blooms that deplete oxygen in the water and kill marine life.
So scientists added an E. Coli bacteria and mouse DNA to a pig embryo. This
modification decreases a pig’s phosphorous output by as much as 70 percent — making
the pig more environmentally friendly.
Pollution-fighting plants
Scientists at the University of Washington are engineering poplar trees that can clean up
contamination sites by absorbing groundwater pollutants through their roots. The plants
then break the pollutants down into harmless byproducts that are incorporated into their
roots, stems and leaves or released into the air.
In laboratory tests, the transgenic plants are able to remove as much as 91 percent of
trichloroethylene — the most common groundwater contaminant at U.S. Superfund sites
— out of a liquid solution. Regular poplar plants removed just 3 percent of the
contaminant.
Venomous cabbage
Scientists have recently taken the gene that programs poison in scorpion tails and looked
for ways to combine it with cabbage. Why would they want to create venomous
cabbage? To limit pesticide use while still preventing caterpillars from damaging cabbage
crops. These genetically modified cabbages would produce scorpion poison that kills
caterpillars when they bite leaves — but the toxin is modified so it isn’t harmful to
humans.
Web-spinning goats
Strong, flexible spider silk is one of the most valuable materials in nature, and it could be
used to make an array of products — from artificial ligaments to parachute cords — if we
could just produce it on a commercial scale. In 2000, Nexia Biotechnologies announced it
had the answer: a goat that produced spiders’ web protein in its milk.
Researchers inserted a spiders’ dragline silk gene into the goats’ DNA in such a way that
the goats would make the silk protein only in their milk. This “silk milk” could then be used
to manufacture a web-like material called Biosteel.
Flavr Savr tomato
The Flavr Savr tomato was the first commercially grown genetically engineered food to
be granted a license for human consumption. By adding an antisense gene, the
California-based company Calgene hoped to slow the ripening process of the tomato to
prevent softening and rotting, while allowing the tomato to retain its natural flavor and
color.
The FDA approved the Flavr Savr in 1994; however, the tomatoes were so delicate that
they were difficult to transport, and they were off the market by 1997. On top of
production and shipping problems, the tomatoes were also reported to have a very bland
taste: “The Flavr Savr tomatoes didn’t taste that good because of the variety from which
they were developed. There was very little flavor to save,” said Christ Watkins, a
horticulture professor at Cornell University.
Banana vaccines
People may soon be getting vaccinated for diseases like hepatitis B and cholera by
simply taking a bite of banana. Researchers have successfully engineered bananas,
potatoes, lettuce, carrots and tobacco to produce vaccines, but they say bananas are the
ideal production and delivery vehicle.
When an altered form of a virus is injected into a banana sapling, the virus’ genetic
material quickly becomes a permanent part of the plant’s cells. As the plant grows, its
cells produce the virus proteins — but not the infectious part of the virus. When people
eat a bite of a genetically engineered banana, which is full of virus proteins, their immune
systems build up antibodies to fight the disease — just like a traditional vaccine.
Less-flatulent cows
Cows produce significant amounts of methane as a result of their digestion process —
it’s produced by a bacterium that’s a byproduct of cows’ high-cellulosic diets that include
grass and hay. Methane is a major contributor — second only to carbon dioxide — to the
greenhouse effect, so scientists have been working to genetically engineer a cow that
produces less methane.
Agriculture research scientists at the University of Alberta have identified the bacterium
responsible for producing methane and designed a line of cattle that creates 25 percent
less methane than the average cow.
Genetically modified trees
Trees are being genetically altered to grow faster, yield better wood and even detect
biological attacks. Proponents of genetically engineered trees say biotechnology can help
reverse deforestation while satisfying demand for wood and paper products. For
example, Australian eucalyptus trees have been altered to withstand freezing
temperatures, and loblolly pines have been created with less lignin, the substance that
gives trees their rigidity. In 2003, the Pentagon even awarded Colorado State
researchers $500,000 to develop pine trees that change color when exposed to biological
or chemical attack.
However, critics argue that not enough is known about designer trees’ effect on their
natural surroundings — they could spread their genes to natural trees or increase wildfire
risk, among other drawbacks. Still, the USDA in June gave approval for ArborGen, a
biotechnology company, to begin field trials for 250,000 trees in seven southern states.
Medicinal eggs
British scientists have created a breed of genetically modified hens that produce cancerfighting medicines in their eggs. The animals have had human genes added to their DNA
so that human proteins are secreted into the whites of their eggs, along with complex
medicinal proteins similar to drugs used to treat skin cancer and other diseases.
What exactly do these disease-fighting eggscontain? The hens lay eggs that have
miR24, a molecule with potential for treating malignant melanoma and arthritis, and
human interferon b-1a, an antiviral drug that resembles modern treatments for multiple
sclerosis.
Super carbon-capturing plants
Humans add about nine gigatons of carbon to the atmosphere annually, and plants and
trees absorb about five of those gigatons. The remaining carbon contributes to the
greenhouse effect and global warming, but scientists are working to create genetically
engineered plants and trees that are optimized for capturing this excess carbon.
Carbon can spend decades housed in the leaves, branches, seeds and flowers of plants;
however, carbon allocated to a plant’s roots can spend centuries there. Therefore,
researchers hope to create bioenergy crops with large root systems that can capture and
store carbon underground. Scientists are currently working to genetically modify
perennials like switchgrass and Miscanthus because of their extensive root systems.
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