Tag Archives: DNA

Chickens help fight cancer

Britney may help fight cancer

The scientists who made history by cloning Dolly the sheep have unveiled their latest creation – a chicken called Britney.

She is the first of four fowl genetically altered so they will be able to provide cancer-fighting agents in their eggs. The experts at the Roslin Institute near Edinburgh hope GM chickens will be used in the future to mass-produce cancer drugs.

They plan to be making new drugs to fight skin cancer from chickens like Britney and her friends within a year. Fresh treatments for lung, cervical and breast cancers will follow, they believe.

Many cancer drugs being developed are protein-based but they are complex and difficult to produce in large quantities using traditional manufacturing methods.

By genetically modifying chickens –introducing DNA which makes them produce cancer-fighting proteins – the scientists say the drugs can be manufactured by the ton.

The institute is linking up with the biotechnology company Viragen. The scientists are to introduce the firm’s patented cancer antibodies into their GM chickens so the vital proteins will be produced in the whites of the fowl’s eggs.

Chickens lay an average of 250 eggs a year and are natural protein producers. They are also cheap. So GM hens could turn out to be highly efficient living drugs factories.

Dr Helen Sang, from the Roslin Institute, said yesterday: ‘Avian technology provides a much faster, cheaper and virtually unlimited production process marked by the chicken’s prolific egg laying capacity.’

Any drugs produced using GM chickens would have to undergo lengthy clinical trials before they being made commercially available.

Viragen hope to have trials going within two years.

Although Dr Sang’s team has managed to produce ‘transgenic’ chickens – birds which have had their DNA scientifically altered – the process is inefficient, with only a handful of attempts succeeding.

If the chickens could be cloned, like Dolly the sheep, the success rate could be 100 per cent. The scientists are working towards cloning a chicken.

‘We cannot put a time scale on it,’ said Professor Grahame Bulfield, director of the Roslin Institute. ‘But there is no reason why we shouldn’t be able to adapt the technology for chickens.

‘Production of these proteins is still viable using transgenic chickens, but it would be much more efficient with clones.’

The developments at the institute will reignite the ethical debate over the rights and wrongs of so-called ‘pharming’, the use of genetically altered animals to produce drugs.

Dr Andre Menache, president of Doctors and Lawyers for Responsible Medicine, said he had ethical concerns about using animals as ‘manufacturing plants’. ‘But my main worry about this is in terms of public health,’ he added.

‘After BSE, we should be very, very careful about using animal products in people. We could be transmitting something unknown. ‘By creating transgenic creatures, we are producing something new and about which there are many unanswered questions.

‘All kinds of safety hurdles need to be overcome before we start using drugs from transgenic animals. ‘I am not convinced that socalled pharming presents no risk to public health.’

Source: http://www.dailymail.co.uk/health/article-7939/Chickens-help-fight-cancer.html#ixzz2RrhPAiFb


Dinochicken – the sequel

Joe PuglieseJack Horner is Regents’ professor of paleontology at Montana State University and the curator of paleontology at the Museum of the Rockies in Bozeman, Montana. Horner, who discovered the first dinosaur eggs in the Western Hemisphere, was the technical adviser to Steven Spielberg for the movie “Jurassic Park” and its sequel. He spoke at the TED conference in Long Beach, California in March.

“When I was a young boy, I dreamed of two things: one, to become a paleontologist, and another, to have a pet dinosaur. I have become a paleontologist, and now I strive to figure out a way to bring back or create my living dinosaur.

I was very fortunate during my early years as a paleontologist, in that my field crews and I made some remarkable discoveries indicating dinosaurs to have been extremely social. We found a dinosaur nesting ground with clutches of eggs and nests containing the skeletons of babies, and massive accumulations of juvenile and adult skeletons. These discoveries led to our current understanding of dinosaurs as colonial nesters and good parents, and animals that traveled in gigantic herds.

These social behaviors were depicted in Michael Crichton’s novel and Steven Spielberg’s movie “Jurassic Park.” But it was the book and movie’s premise that dinosaurs could be brought back to life — from DNA found in insects that bit the dinosaurs — that interested me the most.

Some scientists had attempted to retrieve DNA from insects in amber, and unfortunately, they had not found it possible. In 1993, when the movie was released, my graduate student Mary Schweitzer and I got a National Science Foundation grant to attempt to extract DNA from a Tyrannosaurus rex skeleton.

Alas, we didn’t find DNA in the dinosaur either, but Mary went on to discover soft tissues and even proteins in another T-rex we excavated in 2001.

Photo: Dan ForbesBut even though we didn’t find DNA in an extinct dinosaur, I decided to see if we could retro-engineer a living dinosaur — all birds are living dinosaurs — and make it look like an extinct dinosaur.

My colleague Hans Larsson, using developmental biology techniques at McGill University, was studying the transition between extinct dinosaurs and birds, trying to understand how birds came to lose their tails and transform hands to wings. I figured if he could figure this out, we could reverse the methods and make a bird with hands and a tail. It was the beginning of the “Build a Dinosaur Project.”

The Build a Dinosaur Project continues as researchers attempt to identify two atavistic genes proposed to control the appearance of the three-fingered hand and the primitive tail. This search involves the knocking out of target genes in early developing chicken embryos.

This is a long process that can take years — so as we wait, the prospect of a chicken-dinosaur is being used as a medium to explain developmental biology and evolutionary biology to the general public.

It is a simple way to demonstrate how evolution works, by showing that the genes for these primitive characteristics continue to reside in DNA — even when they are of no particular use at the present, but when they might be useful in the animal’s evolutionary future. The chicken-dinosaur is also an icon for genetic engineering in animals, providing a focus for discussions concerning ethics.

story chickenosaurus courtesy.jpg

It is interesting, for example, that some people consider simple genetic engineering, such as the dino-chicken, to be unethical, while they find selective breeding — potentially producing the same results over time — to be an ethical endeavor.

I think of the dino-chicken as a tool to educate people about the extraordinary characteristics of evolution and give them the primer knowledge to make future decisions about these types of biological research. You can read more about this stuff in my book entitled “How To Build a Dinosaur.”

As I stated in my TED talk, this is all about attempting to satisfy the aspirations of sixth-graders (and children of all ages) and bring back dinosaurs or at least something that looks more like a dinosaur than a bird. Unfortunately, our first steps in this process will likely produce an animal that looks like the image above, but it will be a start, and by the time the sixth graders are our research scientists, maybe they will be able to create animals more to their liking.”

Horner’s 2009 book, How to Build a Dinosaur: Extinction Doesn’t Have to Be Forever, describes his plan to recreate a dinosaur by genetically “nudging” the DNA of a chicken. As of 2011 Horner has been pursuing the project to develop the animal, which he describes as a “chickenosaurus”, with a team of geneticists.

Gynandromorph chicken

photo;chicken;sex;cells;hybridIt was a tough egg to crack, but scientists have finally explained why some chickens are born half male and half female.

The bodies of these hen-rooster hybrids, or gynandromorphs, have a mixture of genetically male and female cells, the research reveals.

Only about 1 in 10,000 chickens are born as gynandromorphs, which have male features—such as a rooster’s comb and a defensive leg spur—on one side of their bodies and dainty, henlike features on the other.

Researchers had thought a rare genetic abnormality causes the condition. To test this theory, Michael Clinton of the University of Edinburgh and his team analyzed cells from three gynandromorph chickens.

To their surprise, the team found that the chickens’ cells were normal. What was strange, however, was that male cells made up one half of the body, and female cells composed the other half.

Half-Sex Chickens Are Double Fertilized

The scientists believe gynandromorphs are created when a chicken egg becomes fertilized by two sperm.

Despite their dual nature, the hybrid birds typically have one of the sex organs, either testes or ovaries. The scientists did not test whether the chickens could actually reproduce, however.

Gynandromorphs are known to exist in other bird species, such as zebra finches, pigeons, and parrots, Clinton said by email.

It’s likely that the phenomenon occurs in all birds species, he added, but it’s not always obvious because males and females of many species often look similar.

Source: http://news.nationalgeographic.com/news/2010/03/100315-half-male-half-female-chickens/

Why Transylvanian Chickens Have Naked Necks

Transylvanian naked neck chickens.Scientists have cracked why the Transylvanian naked neck chicken has a featherless neck—and it isn’t to give vampires easier access.

The Transylvanian bird‘s naked neck results from a random genetic mutation that causes the overproduction of a feather-blocking molecule called BMP12, a new DNA study shows.

The mutation first arose in domestic chickens in northern Romania hundreds of years ago. The naked neck chicken—also dubbed the churkey or turken—has a chicken-like body but a turkey-like head atop a long, deep-red neck.

Surprisingly, when scientists treated standard-breed chicken embryos with BMP12 in the lab, the young chickens developed no feathers on their necks—suggesting the neck is more sensitive to the molecule, according to study leader Denis Headon, a developmental biologist at the University of Edinburgh’s Roslin Institute.

To find out why, Headon and his team did a further analysis, which revealed an acid derived from Vitamin A is produced on the chicken’s neck skin. The acid essentially enhances the BMP molecule’s effects, making the birds’ necks bare, they found.

Naked-Necked Birds Can Handle the Heat

Unlike most genetic mutations, which are generally bad for an animal, the naked-neck tweak has increased naked necks’ popularity worldwide.

That’s because bare-necked birds are more resistant to heat and thus produce better meat and eggs—especially crucial for poultry producers in hot climates such as Mexico‘s, Headon said.

And naked necks aren’t alone: “We think all birds have this priming or readiness to lose neck feathers first,” he noted.

“Once you have a mutation that increases BMP12 in skin, the neck is the region that’s ready to lose its feathers—it’s already more sensitive.”

In the wild, for instance, it’s likely that ostriches and storks have lost their neck feathers to stay cool, though it’s unclear whether BMP12 played any role.

“Evolution has always found it easy to lose neck feathers whenever it gets hot and the bird gets big.”

Source: http://news.nationalgeographic.com/news/2011/03/110315-transylvanian-naked-neck-chicken-churkeys-turkens-science/

Duck fathers a chicken, offering hope for extinct species

A duck has fathered a chicken.  Seriously!

Scientists from Dubai’s Central Veterinary Research Laboratory say they have succeeded in using one species to produce another, a new technique which could be used to bring extinct species back to life.

To achieve the interspecies-produced offspring, researchers injected a male duck embryo with chicken germ cells — those cells responsible for producing gametes (sperm or eggs). And as the duck grew into sexual maturity, its body began to produce reproductive cells belonging to the other species, allowing it to breed with a hen to create a chick.

Using this same technique, researchers believe that one day chickens could be modified with DNA from other bird types, like eagles or songbirds, to breed offspring belonging to a species not their own — including those previously wiped out of existence.

Mike McGrew, a scientist working with the team in Dubai, says that the hope is to one day ”use this system to propagate endangered species or potentially bring back an extinct one.”

Not long ago, the notion of reviving lost species from extinction seemed pure science fiction, but embryonic researchers are well on their way to doing just that.

Source: http://www.treehugger.com/natural-sciences/duck-fathers-chicken-offering-hope-extinct-species.html