CLOSE
Original image
CBS/Screenshot

7 Genetically Modified Animals That Glow in the Dark

Original image
CBS/Screenshot

By Lauren Hansen

This is no party trick. These radiant sheep, dogs, and cats help further research of human diseases.

1. Sheep

Good news, nighttime shepherds: Sheep can now glow in the dark. Well, technically, only nine of the wooly animals can. And they're in Uruguay.

When these sheep were born in October 2012, scientists at the Animal Reproductive Institute of Uruguay immediately injected them with a green protein found in the Aequorea Victoria jellyfish. As the sheep grew, they looked and acted like any other four-legged balls of fluff, except that they gave off a greenish glow after being exposed to certain ultraviolet light. Check 'em out:

Typically, these green fluorescent proteins are used to monitor the activity of altered genes. They have proved to be of great help in the study of diseases. In fact, the method's scientific pioneers were awarded the Nobel Prize for chemistry in 2008. In the case of these sheep, scientists hope that one day they'll be able to use this sort of procedure to create animals with super health-boosting milk. Here, a look back at the radiant animals at the center of these genetic studies throughout the last decade.

2. A rabbit

Ekac.org/Chrystelle Fontaine

This endeavor was actually an artistic one. Eduard Kac is an artist known to use genetic engineering techniques to create unique living works of art. In May 2000, Kac introduced the world to his "GFP bunny," an albino rabbit named Alba that glowed fluorescent when exposed to blue light. Alba was actually just one component of the project, which was also supposed to include a public debate about the practice of manipulating genes in animals for research. Kac wanted to conclude the project by taking Alba home to live with his family. A research institute in France actually created the rabbit for Kac — the florescent jellyfish protein was injected into a fertilized rabbit egg — and later hesitated over releasing the animal due to protests from animal rights groups over Alba's very creation. The scientists also claimed that they never agreed for Kac to take the bunny home. Two years after Alba was born, and long before Alba could make her trip to the states, the unique rabbit died — an abrupt end to the battle between science and art.

3. Pigs

In 2008, scientists in Taiwan claimed to have a world first: Pigs that glowed from the inside out. While other researchers had bred partially fluorescent pigs, these genetically modified pigs had not only glowing skin and eyes, but also organs, including the heart. Scientists added DNA from fluorescent jellyfish to more than 260 pig embryos, which were then implanted into eight different sows, four of which became pregnant. The result was three male piglets whose eyes, teeth, and snouts had a slightly greenish tint during the day, but would glow entirely green in the dark after being introduced to a blue light.

4. Monkeys

E. Sasaki et al 2009

In this 2009 study, the same jellyfish DNA injection was used, but for different purposes. Scientists in Japan wanted to see if the jellyfish gene was inherited by the second generation of a genetically modified monkey. The team at the Central Institute for Experimental Animals in Kawasaki, Japan, added a fluorescent gene to the marmoset embryos, which were then transferred into surrogate females who produced five live births. All of the modified marmosets carried the genes in their body. When they produced offspring, two passed the fluorescent gene onto their young. This was the first time a genetically modified animal passed such genes down a generation. Researchers said it could be a major step in understanding Parkinson's and motor neuron disease.

5. Dogs

A 2009 experiment by a team at Seoul National University reportedly produced the first transgenic dog. Five beagles were created by cloning fibroblast cells that express a red florescent gene produced by sea anemones. Under natural light you can see the faint essence of the red protein under the pale skin. In the dark and under an ultraviolet light, the dogs glow a reddish orange. The five healthy dogs eventually grew to spawn their own florescent offspring. The experiment was meant to prove the principle of transgenic animals, particularly dogs, who, due to their lifespan and reproductive cycle, are good stand-ins for human disease research. Two years later, a team at the same university bred a beagle name Tegon whose fluorescent gene could be controlled. When the dog eats food containing a doxycycline antibiotic and then is exposed to ultraviolet light, it glows green. When the drug is no longer added to the food, the glow eventually fades. Scientists say the study opens opportunities for better understanding genes that trigger fatal diseases, like Alzheimer's and Parkinson's, in humans.

6. Cats

A glowing kitten stands next to a normal cat. Photo courtesy of the Mayo Clinic.

Cats are susceptible to a close relative of HIV called feline immunodeficiency virus. The viral disease infects mostly feral cats, of which there are reportedly a half a billion in the world. In a 2011 study, a team of scientists from the U.S. and Japan inserted a gene into cats that helps them resist this feline form of AIDS. Then, to be able to easily mark the cells, scientists also inserted the green fluorescent protein. Both genes were transferred into feline eggs. They were then able to more readily monitor how the resistant gene developed in the cats' bodies when looking at them under a microscope. Like the other animals, the cats appeared normal during the day, but could glow at night if prompted.

7. Fish

University of Exeter

One of the biggest downsides to helpful industrial products like, say, plastic, or female contraceptives, is that they contain bad chemicals called endocrine disrupters. These substances become pollutants that harm animal and human bodies. They have reportedly been associated with lower sperm counts and breast and testicular cancers. So you can see why scientists may want to study them. The problem has been that it is difficult to track the endocrine disrupters once they enter the body. And so a team of scientists used green fluorescent proteins and genetically engineered zebrafish to glow in places where an endocrine-disrupting chemical is present. As we've previously illustrated, the fluorescent protein doesn't interfere with the body, but, when studied under a microscope, can be easily found. The glowing green areas within the fish then become a roadmap for scientists homing in on the pollutants' potential health impacts.

Sources: ABC NewsBBCDiscovery, The GuardianNational GeographicNBC NewsNew Scientist (2), The RegisterTaipai Times

More from The Week...

How we may Finally get to Witness the Birth of a Black Hole

*

The Stories of 5 Bionic Dogs

*

English Spelling is Terrible. Other Languages are Worse.

Original image
istock
arrow
Animals
14 Fascinating Facts About Foxes
Original image
istock

Foxes live on every continent except Antarctica and thrive in cities, towns, and rural settings. But despite being all around us, they’re a bit of a mystery. Here’s more about this elusive animal.

1. Foxes Are Solitary.

Foxes are part of the Canidae family, which means they’re related to wolves, jackals, and dogs. They’re medium-sized, between 7 and 15 pounds, with pointy faces, lithe frames, and bushy tails. But unlike their relatives, foxes are not pack animals. When raising their young, they live in small families—called a “leash of foxes” or a “skulk of foxes”—in underground burrows. Otherwise, they hunt and sleep alone.

2. Foxes Have A Lot In Common With Cats.

Like the cat, the fox is most active after the sun goes down. In fact, it has vertically oriented pupils that allow it to see in dim light. It even hunts in a similar manner to a cat, by stalking and pouncing on its prey.

And that’s just the beginning of the similarities. Like the cat, the fox has sensitive whiskers and spines on its tongue. It walks on its toes, which accounts for its elegant, cat-like tread. And—get this—many foxes have retractable claws that allow them to climb rooftops or trees. Some foxes even sleep in trees—just like cats.

3. The Red Fox Is The Most Common Fox.

The red fox has the widest geographical range of any animal in the order Carnivora. While its natural habitat is a mixed landscape of scrub and woodland, its flexible diet allows it to adapt to many environments. As a result, its range is the entire Northern Hemisphere, from the Arctic Circle to North Africa to Central America to the Asiatic steppes. It’s also in Australia, where it’s considered an invasive species.

4. Foxes Use The Earth’s Magnetic Field.

Like a guided missile, the fox harnesses the earth’s magnetic field to hunt. Other animals, like birds, sharks, and turtles, have this “magnetic sense,” but the fox is the first one we’ve discovered that uses it to catch prey.

According to New Scientist, the fox can see the earth’s magnetic field as a “ring of shadow” on its eyes that darkens as it heads towards magnetic north. When the shadow and the sound the prey is making line up, it’s time to pounce. Here’s the fox in action:

5. Foxes Are Good Parents.

Foxes reproduce once a year. Litters range from one to 11 pups (the average is six), which are born blind and don’t open their eyes until nine days after birth. During that time, they stay with the vixen (female) in the den while the dog (male) brings them food. They live with their parents until they're seven months old. The vixen protects her pups with surprising loyalty. Recently, a fox pup was caught in a trap in England for two weeks, but survived because its mother brought it food every day.

6. The Smallest Fox Weighs Under 3 Pounds.

Roughly the size of a kitten, the fennec fox has elongated ears and a creamy coat. It lives in the Sahara Desert, where it sleeps during the day to protect it from the searing heat. Its ears not only allow it to hear prey, they also radiate body heat, which keeps the fox cool. Its paws are covered with fur so that the fox can walk on hot sand, like it’s wearing snowshoes.

7. Foxes Are Playful.

Foxes are known to be friendly and curious. They play among themselves as well as with other animals like cats and dogs. They love balls, which they frequently steal from golf courses.

Although foxes are wild animals, their relationship with humans goes way back. In 2011, researchers opened a grave in a 16,500-year-old cemetery in Jordan to find the remains of a man and his pet fox. This was 4000 years before the first-known human and dog were buried together.

8. You Can Buy A Pet Fox.

In the 1960s, a Soviet geneticist named Dmitry Belyaev bred thousands of foxes before achieving a domesticated fox. Unlike a tame fox, which has learned to tolerate humans, a domesticated fox is docile toward people from birth. Today, you can buy a pet fox for $9000, according to Fast Company. They’re reportedly curious and sweet-tempered, although inclined to dig in your furniture.

9. Arctic Foxes Don’t Shiver Until –70 degrees Celsius.

The arctic fox, which lives in the northernmost areas of the hemisphere, can handle cold better than most animals on earth. It doesn’t even get cold until –70 degrees Celsius. Its white coat also camouflages it against predators. As the seasons change, the coat changes too, turning brown or gray so the fox can blend in with the rocks and dirt of the tundra.

10. Fox Hunting Continues To Be Controversial.

Perhaps because of the fox’s ability to decimate a chicken coop, in the 16th century, fox hunting became a popular activity in Britain. In the 19th century, the upper classes turned fox hunting into a formalized sport where a pack of hounds and men on horseback chase a fox until it is killed. Today, whether to ban fox hunting continues to be a controversial subject in the UK. Currently, fox hunting with dogs is not allowed.

11. The Fox Appears Throughout Folklore.

Examples include: the nine-tail fox from various Asian cultures; the Reynard tales from medieval Europe; the sly trickster fox from Native American lore; and Aesop’s “The Fox and the Crow.” The Finnish believed a fox made the Northern Lights by running in the snow so that its tail swept sparks into the sky. From this, we get the phrase “fox fires.”

12. Bat-eared Foxes Listen For Insects.

The bat-eared fox is aptly named, not just because of its 5-inch ears, but because of what it uses those ears for—like the bat, it listens for insects. On a typical night, the fox walks along the African Savannah, listening, until it hears the scuttle of prey. Although the fox eats a variety of insects and lizards, most of its diet is made up of termites. In fact, the bat-eared fox often makes its home in termite mounds, which it usually cleans out of inhabitants before moving in.

13. Darwin Discovered A Fox Species.

During his voyage on the Beagle, Charles Darwin collected a fox that today is unimaginatively called Darwin’s Fox. This small gray fox is critically endangered and lives in just two spots in the world: One population is on Island of Chiloé in Chile, and the second is in a Chilean national park. The fox’s greatest threats are unleashed domestic dogs that carry diseases like rabies.

14. Foxes Sound Like This.

Foxes make 40 different sounds, some of which you can listen to here. The most startling is the scream:

Pleasant dreams!

All images courtesy of iStock unless otherwise stated.

Original image
iStock
arrow
Big Questions
Why Do Cats Love Scratching Furniture?
Original image
iStock

Allergy suffering aside, cat ownership has proven health benefits. A feline friend can aid in the grieving process, reduce anxiety, and offer companionship.

The con in the cat column? They have no reservations about turning your furniture into shredded pleather. No matter how expensive your living room set, these furry troublemakers will treat it with the respect accorded to a college futon. Do cats do this out of some kind of spite? Are they conspiring with Raymour & Flanigan to get you to keep updating home decor?

Neither. According to cat behaviorists, cats gravitate toward scratching furniture mostly because that love seat is in a really conspicuous area [PDF]. As a result, cats want to send a message to any other animal that may happen by: namely, that this plush seating belongs to the cat who marked it. Scratching provides both visual evidence (claw marks) as well as a scent marker. Cat paws have scent glands that can leave smells that are detectable to other cats and animals.

But it’s not just territorial: Cats also scratch to remove sloughed-off nail tips, allowing fresh nail growth to occur. And they can work out their knotted back muscles—cramped from sleeping 16 hours a day, no doubt—by kneading the soft foam of a sectional.

If you want to dissuade your cat from such behavior, purchasing a scratching post is a good start. Make sure it’s non-carpeted—their nails can get caught on the fibers—and tall enough to allow for a good stretch. Most importantly, put it near furniture so cats can mark their hangout in high-traffic areas. A good post might be a little more expensive, but will likely result in fewer trips to Ethan Allen.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios