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7 Genetically Modified Animals That Glow in the Dark

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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

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Big Questions
Why Do We Dive With Sharks But Not Crocodiles?
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Why do we dive with sharks but not crocodiles?

Eli Rosenberg:

The issue is the assumption that sharks' instincts are stronger and more basic.

There are a couple of reasons swimming with sharks is safer:

1. Most sharks do not like the way people taste. They expect their prey to taste a certain way, like fish/seal, and we do not taste like that. Sharks also do not like the sensation of eating people. Bigger sharks like great whites enjoy prey with a high fat-bone ratio like seals. Smaller sharks enjoy eating fish, which they can gobble in one bite. So, while they might bite us, they pretty quickly decide “That’s not for me” and swim away. There is only one shark that doesn’t really care about humans tasting icky: that shark is our good friend the tiger shark. He is one of the most dangerous species because of his nondiscriminatory taste (he’s called the garbage can of the sea)!

2. Sharks are not animals that enjoy a fight. Our big friend the great white enjoys ambushing seals. This sneak attack is why it sometimes mistakes people for seals or sea turtles. Sharks do not need to fight for food. The vast majority of sharks species are not territorial (some are, like the blacktip and bull). The ones that are territorial tend to be the more aggressive species that are more dangerous to dive with.

3. Sharks attacked about 81 people in 2016, according to the University of Florida. Only four were fatal. Most were surfers.

4. Meanwhile, this is the saltwater crocodile. The saltwater crocodile is not a big, fishy friend, like the shark. He is an opportunistic, aggressive, giant beast.


5. Crocodiles attack hundreds to thousands of people every single year. Depending on the species, one-third to one-half are fatal. You have a better chance of survival if you played Russian roulette.

6. The Death Roll. When a crocodile wants to kill something big, the crocodile grabs it and rolls. This drowns and disorients the victim (you). Here is a PG video of the death roll. (There is also a video on YouTube in which a man stuck his arm into an alligator’s mouth and he death rolled. You don’t want to see what happened.)

7. Remember how the shark doesn’t want to eat you or fight you? This primordial beast will eat you and enjoy it. There is a crocodile dubbed Gustave, who has allegedly killed around 300 people. (I personally believe 300 is a hyped number and the true number might be around 100, but yikes, that’s a lot). Gustave has reportedly killed people for funsies. He’s killed them and gone back to his business. So maybe they won’t even eat you.


8. Sharks are mostly predictable. Crocodiles are completely unpredictable.

9. Are you in the water or by the edge of the water? You are fair game to a crocodile.

10. Crocodiles have been known to hang out together. The friend group that murders together eats together. Basks of crocodiles have even murdered hippopotamuses, the murder river horse. Do you think you don't look like an appetizer?

11. Wow, look at this. This blacktip swims among the beautiful coral, surrounded by crystal clear waters and staggering biodiversity. I want to swim there!

Oh wow, such mud. I can’t say I feel the urge to take a dip. (Thanks to all who pointed this out!)

12. This is not swimming with the crocodiles. More like a 3D aquarium.

This post originally appeared on Quora. Click here to view.

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Animals
10 Filling Facts About Turkeys
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Don’t be fooled by their reputation for being thoughtless. These roly-poly birds have a few tricks up their wings.

1. THE BIRDS WERE NAMED AFTER THE COUNTRY.

The turkey is an American bird, so why does it share its name with a country on the other side of the world? Laziness, mostly. Turkish traders had been importing African guinea fowl to Europe for some time when North American explorers started shipping M. gallopavo back to the Old World. The American birds looked kind of like the African “turkey-cocks,” and so Europeans called them “turkeys.” Eventually, the word “turkey” came to describe M. gallopavo exclusively.

2. THEY NEARLY WENT EXTINCT.

By the early 20th century, the combination of overzealous hunting and habitat destruction had dwindled the turkey populations down to 30,000. With the help of conservationists, the turkey made a comeback. The birds are now so numerous that they’ve become a nuisance in some parts of the country.

3. THEY’VE GOT TWO STOMACHS.

Like all birds, turkeys don’t have teeth, so they’ve got to enlist some extra help to break down their food. Each swallowed mouthful goes first into a chamber called a proventriculus, which uses stomach acid to start softening the food. From there, food travels to the gizzard, where specialized muscles smash it into smaller pieces.

4. FEMALE TURKEYS DON’T GOBBLE.

Turkeys of both sexes purr, whistle, cackle, and yelp, but only the males gobble. A gobble is the male turkey’s version of a lion’s roar, announcing his presence to females and warning his rivals to stay away. To maximize the range of their calls, male turkeys often gobble from the treetops.

5. THEY SLEEP IN TREES.

Due to their deliciousness, turkeys have a lot of natural predators. As the sun goes down, the turkeys go up—into the trees. They start by flying onto a low branch, then clumsily hop their way upward, branch by branch, until they reach a safe height.

6. BOTH MALE AND FEMALE TURKEYS HAVE WATTLES.

The wattle is the red dangly bit under the turkey’s chin. The red thing on top of the beak is called a snood. Both sexes have those, too, but they’re more functional in male turkeys. Studies have shown that female turkeys prefer mates with longer snoods, which may indicate health and good genes.

7. THEY HAVE REALLY GOOD VISION.

Turkey eyes are really, really sharp. On top of that, they’ve got terrific peripheral vision. We humans can only see about 180 degrees, but given the placement of their eyes on the sides of their heads, turkeys can see 270 degrees. They’ve also got way better color vision than we do and can see ultraviolet light.

8. THEY’RE FAST ON THE GROUND, TOO.

You wouldn’t guess it by looking at them, but turkeys can really book it when they need to. We already know they’re fast in the air; on land, a running turkey can reach a speed of up to 25 mph—as fast as a charging elephant.

9. THEY’RE SMART … BUT NOT THAT SMART.

Turkeys can recognize each other by sound, and they can visualize a map of their territory. They can also plan ahead and recognize patterns. In other ways, they’re very, very simple animals. Male turkeys will attack anything that looks remotely like a threat, including their own reflections in windows and car doors.

10. IN THE EVENT OF A TURKEY ATTACK, CALL THE POLICE.

They might look silly, but a belligerent turkey is no joke. Male turkeys work very hard to impress other turkeys, and what could be more impressive than attacking a bigger animal? Turkey behavior experts advise those who find themselves in close quarters with the big birds to call the police if things get mean. Until the authorities arrive, they say, your best bet is to make yourself as big and imposing as you possibly can.

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