Posted : December 2010
Author : draganescu
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.
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.
Venomous cabbage
Scientists have recently taken the gene that programs poison
in scorpion tails and combined 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 produce
scorpion poison that kills caterpillars when they bite leaves - but the toxin
is modified so it isn’t harmful to humans.
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.
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.
Medicinal eggs
British scientists have created a breed of genetically
modified hens that produce cancer-fighting 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 eggs contain? The hens lay eggs that
have miR24, an antibody with potential for treating malignant melanoma and
arthritis, and human interferon b-1a, an antiviral drug that resembles modern
treatments for multiple sclerosis.
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.
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.
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.
Fast-growing salmon
AquaBounty’s genetically modified salmon grows twice as fast
as the conventional variety - the photo shows two same-age salmon with the
genetically altered one in the rear. The company says the fish has the same
flavor, texture, color and odor as a regular salmon; however, the debate
continues over whether the fish is safe to eat.
Genetically engineered Atlantic salmon has an added growth hormone from a
Chinook salmon that allows the fish to produce growth hormone year-round.
Scientists were able to keep the hormone active by using a gene from an
eel-like fish called an ocean pout, which acts as an “on switch” for the
hormone.
If the FDA approves the sale of the salmon, it will be the first time the
government has allowed modified animals to be marketed for human consumption.
According to federal guidelines, the fish would not have to be labeled as
genetically modified.
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..
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.
~Blog Admin~
No comments:
Post a Comment