New Orleans — Everyone knows that cats can see in the dark, but that wasn’t good enough for some New Orleans scientists. They produced Mr. Green Genes, a cat that glows in the dark and is destined to be more than just a novelty for Halloween parties.
He’s a nearly 6-month-old orange tabby but, under ultraviolet light, his eyes, gums and tongue glow a vivid lime green, the result of a genetic experiment at the Audubon Center for Research of Endangered Species.
Mr. Green Genes is the first fluorescent cat in the United States, said Betsy Dresser, the center’s director.
The researchers made him so they could learn whether a gene could be introduced harmlessly into the feline’s genetic sequence to create what is formally known as a transgenic cat. If so, it would be the first step in a process that could lead to the development of ways to combat diseases via gene therapy.
The gene, which was added to Mr. Green Genes’ DNA when he was created earlier this year in the Audubon center’s laboratory, has no effect on his health, Dresser said.
Cats are ideal for this project because their genetic makeup is similar to that of humans, said Dr. Martha Gomez, a veterinarian and staff scientist at the center.
Why a glowing cat?
To show that the gene went where it was supposed to go, the researchers settled on one that would glow.
The gene “is just a marker,” said Leslie Lyons, an assistant professor of population health and reproduction at the School of Veterinary Medicine at the University of California, Davis, who is familiar with the Audubon center’s work.
“The glowing part is the fun part,” she said.
Glowing creatures made international news earlier this month when the Nobel Prize in Chemistry was awarded to three scientists who had discovered the gene through their work with jellyfish. They used the gene, whose formal name is enhanced green fluorescence protein, to see how things work inside animals and even inside cells.
Mr. Green Genes — his name comes from Mr. Green Jeans, a character on the long-departed “Captain Kangaroo” television show — is deeply suspicious of strangers. He spends most of his days napping, and he doesn’t like being held when he doesn’t want to be cuddled.
In normal light, the 7-pound cat, who lives at the center, looks and acts like any other feline.
But turn out the room lights and switch on some black light, and you can see glowing ears, nostrils, eyes and gums. Those body parts light up because the protein is more likely to express itself in mucous membranes, Lyons said.
“You can’t lose that cat at night,” said C. Earle Pope, the center’s senior scientist.
“The frozen zoo”
In theory, his litter box could glow, too, because cat droppings include epithelial cells, where the gene can be found. But there is entirely too much other stuff around them to allow for readily visible glowing without messy lab work, Gomez said.
The Audubon center started its animal-cloning experiments in 2001. Two years later, Ditteaux, an African wildcat, was born there. He was the world’s first cloned wild carnivore.
Cloning starts with cells — generally skin cells, Gomez said, because retrieval isn’t too invasive — and the cells’ genetic material is stored in a tank of liquid nitrogen where the temperature is 316 degrees below zero. The Audubon center has 12 such tanks of genetic specimens awaiting use; Dresser calls them “the frozen zoo.”
For work with felines, eggs are collected from a donor cat — usually a domestic cat — and the DNA is removed and replaced. To create Mr. Green Genes, the fresh DNA included the fluorescent gene.
Then the fertilized egg is inserted into a surrogate mother cat for a pregnancy lasting 65 to 70 days.
After Ditteaux’s arrival, Gomez was invited to discuss it before a group of gene-therapy specialists, who, she said, were interested in the prospect of creating a genetic model for fighting diseases.
A tool to spot cystic-fibrosis
The Audubon scientists want to use their technique to develop a gene-therapy treatment for cystic fibrosis, an incurable hereditary disease for which, Gomez said, there are no gene-therapy models.
The fluorescence gene will go alongside the cystic-fibrosis gene and make it easy to spot. The long-term goal of this process, for which there is no timetable, is the production of what Gomez calls a “knockout gene.”
Work on this project is under way, she said. “We are getting some preliminary data, but we don’t have the full funds for it.”
Mr. Green Genes’ next role for the center will combine science and sex. He will become a stud so the Audubon team can determine whether the fluorescence gene can be transmitted. That should take no more than two breeding cycles, Gomez said.
“If he is fertile and if the female is fertile, it should be quick,” she said. “The idea is not to have a lot of green cats around, but to demonstrate that the gene can be passed.”
After that, he will retire to Gomez’s home, where two cats already live.
“I feel that he is my baby,” said Gomez, who led the team that created him.
“You have to realize that this is our first transgenic cat,” she said. “I don’t want him to go to just anybody. I feel he is mine.”
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