What might they decide to do next? The animal kingdom has been increased with some new varieties. Hopefully, man’s attempts to change our world will actually yield benefits. At least here you could find your pet at night.
Cats that can glow in the dark from a new genetic engineering technique are helping scientists study molecules that could stop AIDS, researchers announced Sept. 11.
So far, the researchers have created three genetically engineered kittens that can glow green and pass this gene onto their offspring. They explained that cats are much better models for AIDS viruses than are mice and other animals. [See Images of the Glowing Kittens]
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In addition to opening a window into the virus in humans, the cat research may end up helping the felines themselves, the researchers said.
Devastating AIDS pandemics
The world is currently facing two devastating AIDS pandemics— one in humans, the other in domestic cats. The viruses responsible, human immunodeficiency virus (HIV) and feline immunodeficiency virus (FIV), are highly similar.
“FIV causes AIDS with loss of infection-fighting T cells like HIV does in people, and cats get sick from virtually the same AIDS-defining opportunistic infections as humans who have untreated HIV,” said researcher Eric Poeschla, a molecular biologist and infectious disease specialist at the Mayo Clinic College of Medicine in Rochester, Minn. [10 Deadly Diseases That Hopped Across Species]
As such, researchers have long wanted to genetically experiment with cats to better understand how to combat AIDS. To create genetically modified animals, scientists insert genes into their genomes, often using benign viruses as the delivery vehicles. Investigators commonly target the earliest possible stages in an animal’s development so the gene gets installed into all of its cells — any later, and the gene can end up in some tissues but not others.
Tinkering with cat genes
At first scientists created genetically engineered cats using cloning, which meant injecting a gene into one cell — from the skin, for instance — and then implanting the modified nucleus of that cell into an egg cell that had its nucleus removed; the resulting cell then develops into an embryo much like a fertilized egg would. In this manner, researchers generated felines that were either fluorescent red or green, a glow-in-the-dark cat being visible proof of the genetic engineering succeeding.
However, this kind of cloning is very difficult to perform, as it essentially involves delicate surgery on cells. In addition, the manhandling that both nucleus and egg experience and the “reprogramming” the nucleus undergoes from adult to embryonic status often leads to animals that might look normal but can have aberrations on the molecular and cellular level.
Now scientists have developed a new way to create genetically engineered domestic cats where they modify egg cells directly with viruses. The amount of genetic material they implanted within the cats was tiny — if the entire string of DNA that is the cat genome were unraveled and depicted as a highway reaching across the United States from New York to Los Angeles, the inserted material would be equal in length to one of the dashed yellow lines in the middle of the highway somewhere out in Nebraska, Poeschla said.
This efficient process, the first time sex cells of a carnivore have been genetically modified, led to embryos that robustly expressed the implanted gene without all the complexities cloning can involve. The result — three healthy kittens that glowed green when a blue light was shone on them and transmitted the gene to their offspring.
The researchers then applied this approach to investigating resistance to AIDS.
“We want to see if we can protect the domestic cat against its AIDS virus, if we can protect any species, eventually including ours, against its own AIDS virus,” Poeschla told LiveScience. The aim of future treatments is a gene therapy that can introduce protective genes into people that help them fight off HIV, he added. [AIDS: A Winnable Public Health Battle?]
To do so, they created transgenic cats that generated or expressed antiviral proteins taken from rhesus monkeys.