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SCIENCE & ANIMALS: Green-glowing GE cats are new tool in AIDS research



                                  PART 1


------------------------------- GENET-news -------------------------------

TITLE:   GREEN-GLOWING CATS ARE NEW TOOL IN AIDS RESEARCH

SOURCE:  Thomson Reuters, USA

AUTHOR:  Julie Steenhuysen

URL:     http://www.reuters.com/article/2011/09/11/us-cats-aids-idUSTRE78A2LY20110911

DATE:    11.09.2011

SUMMARY: "U.S. scientists have developed a strain of green-glowing cats with cells that resist infection from a virus that causes feline AIDS, a finding that may help prevent the disease in cats and advance AIDS research in people. [...] ?This provides the unprecedented capability to study the effects of giving AIDS-protection genes into an AIDS-vulnerable animal,? Dr. Eric Poeschla of the Mayo Clinic in Rochester, Minnesota, who led the study, said in a telephone interview."

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GREEN-GLOWING CATS ARE NEW TOOL IN AIDS RESEARCH

(Reuters) - U.S. scientists have developed a strain of green-glowing cats with cells that resist infection from a virus that causes feline AIDS, a finding that may help prevent the disease in cats and advance AIDS research in people.

The study, published on Sunday in the journal Nature Methods, involved inserting monkey genes that block the virus into feline eggs, or oocytes, before they are fertilized.

The scientists also inserted jellyfish genes that make the modified cells glow an eerie green color -- making the altered genes easy to spot.

Tests on cells taken from the cats show they are resistant to feline immunodeficiency virus, or FIV, which causes AIDS in cats.

?This provides the unprecedented capability to study the effects of giving AIDS-protection genes into an AIDS-vulnerable animal,? Dr. Eric Poeschla of the Mayo Clinic in Rochester, Minnesota, who led the study, said in a telephone interview.

Poeschla said that besides people, cats and to some extent, chimpanzees, are the only mammals that develop a naturally occurring virus that causes AIDS.

?Cats suffer from this all over the world,? he said.

Just as the human immunodeficiency virus, or HIV, does in people, FIV works by wiping out infection-fighting T-cells.

FIV infects mostly feral cats, of which there are half billion in the world, Poeschla said. It is transmitted by biting, largely by males defending their territory, but companion cats are affected as well.

In both humans and cats, proteins called restriction factors that normally fight off viral infections are defenseless against HIV and FIV because the viruses evolved potent counter-weapons. But certain monkey versions of these restriction factors are capable of fighting the virus and the team used one such gene from the rhesus monkey.

For the team, which included collaborators in Japan, the trick was to get the monkey gene for the restriction factor -- known as TRIMCyp -- into cats to block cells from becoming infected with the virus.

GREEN FLUORESCENT PROTEIN GENE

To do that, they used a harmless virus to insert the genes into the eggs, a process that has already been done in other mammals including mice, pigs, sheep and marmoset monkeys.

To make it easier to check which cells had the monkey gene, the team also inserted a green fluorescent protein gene from the jellyfish Aequorea victoria that makes them glow green.

?We did it to mark cells easily just by looking under the microscope or shining a light on the animal.?

The method worked so well nearly all offspring from the modified eggs have the restriction factor genes. And these defense proteins are made throughout the cat?s body.

The team has mated two of the three original green-glowing cats, which have produced litters totaling eight kittens which make glowing cells as well.

But the point is not to breed generations of disease-resistant, glowing cats. Rather, the team plans to study these felines as a new way to develop treatments for HIV and the feline version of the disease.

Researchers said the work has several potential uses.

?This technology can be applied to a wide range of species, for many of which there are clear applications and potential benefits,? Dr. Laurence Tiley of the University of Cambridge said in a statement.

?It will be interesting to see how enthusiastically this capability in cats is received and adopted by the HIV and neurobiological research communities and what other research opportunities it offers. A representative non-primate animal model would be a fantastic new tool for studying HIV pathogenesis.?

So far, Poeschla?s team has only tested cells taken from the animals and found they were resistant to FIV. But eventually they plan to expose the cats to the virus and see if they are protected.

?If you could show that you confer protection to these animals, it would give us a lot of information about protecting humans,? Poeschla said.

For cats, this may eventually lead to gene therapy or new drug treatments for FIV, he said. (Editing by Eric Beech)



                                  PART 2

------------------------------- GENET-news -------------------------------

TITLE:   GLOWING TRANSGENIC CATS COULD BOOST AIDS RESEARCH

SOURCE:  New Scientist, UK

AUTHOR:  Andy Coghlan

URL:     http://www.newscientist.com/article/dn20896-glowing-transgenic-cats-could-boost-aids-research.html

DATE:    11.09.2011

SUMMARY: "Prosaically named TgCat1, TgCat2 and TgCat3, the GM cats ? now a year old ? glow ghostly green under ultraviolet light because they have been given the green fluorescent protein gene originating from jellyfish. The GM cats also carry an extra monkey gene, called TRIMCyp, which protects rhesus macaques from infection by feline immunodeficiency virus or FIV ? responsible for cat AIDS. By giving the gene to the cats, the team hopes to offer the animals protection from FIV. Their study could help researchers develop and test similar approaches to protecting humans from infection with HIV."

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GLOWING TRANSGENIC CATS COULD BOOST AIDS RESEARCH

Three cats genetically modified to resist feline immunodeficiency virus (FIV) have opened up new avenues for AIDS research.

The research could also help veterinarians combat the virus, which kills millions of feral cats each year and also infects big cats, including lions.

Prosaically named TgCat1, TgCat2 and TgCat3, the GM cats ? now a year old ? glow ghostly green under ultraviolet light because they have been given the green fluorescent protein (GFP) gene originating from jellyfish.

The GM cats also carry an extra monkey gene, called TRIMCyp, which protects rhesus macaques from infection by feline immunodeficiency virus or FIV ? responsible for cat AIDS.

By giving the gene to the cats, the team hopes to offer the animals protection from FIV. Their study could help researchers develop and test similar approaches to protecting humans from infection with HIV.

Cat immunity

Already, the researchers have demonstrated that lab cultures of white blood cells from the cats are protected from FIV, and they hope to give the virus to the cats to check whether they are immune to it.

?The animals clearly have the protective gene expressed in all their tissues including the lymph nodes, thymus and spleen,? says Eric Poeschla of the Mayo Clinic College of Medicine in Rochester, Minnesota, who led the research. ?That?s crucial because that?s where the disease really happens, and where you see destruction of T-cells targeted by HIV in humans.?

The animals are not the first GM cats, but the new method is far more efficient and versatile than previous techniques. The first cloned cat, born in 2001, was the only one to survive from 200 embryos, each created by taking an ear cell from cats, removing the nucleus and fusing it with a cat egg cell emptied of its own nucleus.

Poeschla?s technique is far more direct, far more efficient and far simpler, and has already been used successfully to make GM mice, pigs, cows and monkeys. He loads genes of interest into a lentivirus, which he then introduces directly into a cat oocyte, or egg cell. The oocyte loaded with the new genes is then fertilised and placed in the womb of a foster mother.

>From 22 implantations, Poeschla achieved 12 fetuses in five pregnancies, and three live births. And out of the 12 fetuses, 11 successfully incorporated the new genes, demonstrating how efficient the method is.

One surviving male kitten, TgCat1, has already mated with three normal females, siring eight healthy kittens that all carry the implanted genes as well, showing that they are inheritable.

But there are doubts about whether cats will replace monkeys as the staples of HIV research. ?It?s fantastic they?ve created GM cats,? says Theodora Hatziioannou of the Aaron Diamond AIDS Research Center in New York City.

?But what makes research in monkeys so much better is that SIV in monkeys is much more closely related to HIV, so it?s more straightforward to draw conclusions than it would be with FIV.

Journal reference: Nature Methods, DOI: 10.1038/NMETH.1703



                                  PART 3

------------------------------- GENET-news -------------------------------

TITLE:   GLOWING CATS SHED LIGHT ON AIDS

SOURCE:  British Broadcasting Corporation, UK (BBC)

AUTHOR:  

URL:     http://www.bbc.co.uk/news/science-environment-14882008

DATE:    12.09.2011

SUMMARY: "Cats that have been genetically modified to glow in the dark are being used to gain insights into Aids. The scientists inserted one gene into the cats that helps them resist the feline form of Aids. They also inserted a gene that produces a fluorescent protein called GFP, Nature Methods journal reports. [...] The antiviral gene comes from a rhesus macaque, and produces a protein called a restriction factor that can resist Aids-causing viruses affecting other animals."

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GLOWING CATS SHED LIGHT ON AIDS

Cats that have been genetically modified to glow in the dark are being used to gain insights into Aids.

The scientists inserted one gene into the cats that helps them resist the feline form of Aids.

They also inserted a gene that produces a fluorescent protein called GFP, Nature Methods journal reports.

This protein - which is produced naturally in jellyfish - is commonly used in this area of research to monitor the activity of altered genes.

?We did it to mark cells easily just by looking under the microscope or shining a light on the animal,? said Dr Eric Poeschla, from the Mayo Clinic in Rochester, US.

The antiviral gene comes from a rhesus macaque, and produces a protein called a restriction factor that can resist Aids-causing viruses affecting other animals.

The team from the US and Japan then transferred this gene, along with the one for GFP, into feline eggs - known as oocytes.

The method worked so well that nearly all offspring from the modified eggs had the restriction factor genes. And these proteins were made throughout the cats? bodies.

The researchers found that there was reduced replication of the feline Aids virus - known as feline immunodeficiency virus (FIV) - in these cats.

Just as the human immunodeficiency virus, or HIV, does in people, FIV works by wiping out infection-fighting T-cells.

FIV infects mostly feral cats, of which there are half a billion in the world, Dr Poeschla said. It is transmitted by biting, largely by males defending their territory, but companion cats are affected as well.

The method could be applied to studying forms of Aids in other animals

In both humans and cats, proteins called restriction factors that normally fight off viral infections are defenseless against HIV and FIV because the viruses have evolved potent counter-weapons.

But certain monkey versions of these restriction factors are capable of fighting the viruses.

So far, Dr Poeschla?s team has only tested cells taken from the animals and found they were resistant to FIV. But eventually they plan to expose the cats to the virus and see if they are protected.

?If you could show that you confer protection to these animals, it would give us a lot of information about protecting humans,? the Mayo Clinic researcher explained.



                                  PART 4

------------------------------- GENET-news -------------------------------

TITLE:   MAYO CLINIC TEAMS WITH GLOWING CATS AGAINST AIDS, OTHER DISEASES

SOURCE:  Mayo Clinic, USA

AUTHOR:  Press Release

URL:     http://www.mayoclinic.org/news2011-rst/6434.html

DATE:    11.09.2011

SUMMARY: "Mayo Clinic researchers have developed a genome-based immunization strategy to fight feline AIDS and illuminate ways to combat human HIV/AIDS and other diseases. The goal is to create cats with intrinsic immunity to the feline AIDS virus. The findings - called fascinating and landmark by one reviewer - appear in the current online issue of Nature Methods. Feline immunodeficiency virus (FIV) causes AIDS in cats as the human immunodeficiency virus (HIV) does in people: by depleting the body?s infection-fighting T-cells."

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MAYO CLINIC TEAMS WITH GLOWING CATS AGAINST AIDS, OTHER DISEASES

ROCHESTER, Minn. - Mayo Clinic researchers have developed a genome-based immunization strategy to fight feline AIDS and illuminate ways to combat human HIV/AIDS and other diseases. The goal is to create cats with intrinsic immunity to the feline AIDS virus. The findings - called fascinating and landmark by one reviewer - appear in the current online issue of Nature Methods.

Feline immunodeficiency virus (FIV) causes AIDS in cats as the human immunodeficiency virus (HIV) does in people: by depleting the body?s infection-fighting T-cells. The feline and human versions of key proteins that potently defend mammals against virus invasion - termed restriction factors - are ineffective against FIV and HIV respectively. The Mayo team of physicians, virologists, veterinarians and gene therapy researchers, along with collaborators in Japan, sought to mimic the way evolution normally gives rise over vast time spans to protective protein versions. They devised a way to insert effective monkey versions of them into the cat genome.

?One of the best things about this biomedical research is that it is aimed at benefiting both human and feline health,? says Eric Poeschla, M.D., Mayo molecular biologist and leader of the international study. ?It can help cats as much as people.?

Dr. Poeschla treats patients with HIV and researches how the virus replicates. HIV/AIDS has killed over 30 million people and left countless children orphaned, with no effective vaccine on the horizon. Less well known is that millions of cats also suffer and die from FIV/AIDS each year. Since the project concerns ways introduced genes can protect species against viruses, the knowledge and technology it produces might eventually assist conservation of wild feline species, all 36 of which are endangered.

The technique is called gamete-targeted lentiviral transgenesis - essentially, inserting genes into feline oocytes (eggs) before sperm fertilization. Succeeding with it for the first time in a carnivore, the team inserted a gene for a rhesus macaque restriction factor known to block cell infection by FIV, as well as a jellyfish gene for tracking purposes. The latter makes the offspring cats glow green.

The macaque restriction factor, TRIMCyp, blocks FIV by attacking and disabling the virus?s outer shield as it tries to invade a cell. The researchers know that works well in a culture dish and want to determine how it will work in vivo. This specific transgenesis (genome modification) approach will not be used directly for treating people with HIV or cats with FIV, but it will help medical and veterinary researchers understand how restriction factors can be used to advance gene therapy for AIDS caused by either virus.

The method for inserting genes into the feline genome is highly efficient, so that virtually all offspring have the genes. And the defense proteins are made throughout the cat?s body. The cats with the protective genes are thriving and have produced kittens whose cells make the proteins, thus proving that the inserted genes remain active in successive generations.

The other researchers are Pimprapar Wongsrikeao, D.V.M., Ph.D.; Dyana Saenz, Ph.D.; and Tommy Rinkoski, all of Mayo Clinic; and Takeshige Otoi, Ph.D., of Yamaguchi University, Japan. The research was supported by Mayo Clinic and the Helen C. Levitt Foundation. Grants from the National Institutes of Health supported key prior technology developments in the laboratory.

About Mayo Clinic

Mayo Clinic is a nonprofit worldwide leader in medical care, research and education for people from all walks of life. For more information, visit MayoClinic.com or MayoClinic.org/news.



                                  PART 5

------------------------------- GENET-news -------------------------------

TITLE:   KOREAN SCIENTISTS CREATE GLOWING DOG: REPORT

SOURCE:  Thomson Reuters, USA

AUTHOR:  Jeremy Laurence

URL:     http://www.reuters.com/article/2011/07/27/us-korean-glowing-dog-idUSTRE76Q4H420110727

DATE:    27.07.2011

SUMMARY: "South Korean scientists said on Wednesday they have created a glowing dog using a cloning technique that could help find cures for human diseases such as Alzheimer?s and Parkinson?s, Yonhap news agency reported. A research team from Seoul National University said the genetically modified female beagle, named Tegon and born in 2009, has been found to glow fluorescent green under ultraviolet light if given a doxycycline antibiotic, the report said."

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KOREAN SCIENTISTS CREATE GLOWING DOG: REPORT

(Reuters) - South Korean scientists said on Wednesday they have created a glowing dog using a cloning technique that could help find cures for human diseases such as Alzheimer?s and Parkinson?s, Yonhap news agency reported.

A research team from Seoul National University (SNU) said the genetically modified female beagle, named Tegon and born in 2009, has been found to glow fluorescent green under ultraviolet light if given a doxycycline antibiotic, the report said.

The researchers, who completed a two-year test, said the ability to glow can be turned on or off by adding a drug to the dog?s food.

?The creation of Tegon opens new horizons since the gene injected to make the dog glow can be substituted with genes that trigger fatal human diseases,? the news agency quoted lead researcher Byeong-Chun Lee as saying.

He said the dog was created using the somatic cell nuclear transfer technology that the university team used to make the world?s first cloned dog, Snuppy, in 2005.

The scientist said that because there are 268 illnesses that humans and dogs have in common, creating dogs that artificially show such symptoms could aid treatment methods for diseases that afflict humans.

The latest discovery published in Genesis, an international journal, took four years of research with roughly 3.2 billion won ($3 million) spent to make the dog and conduct the necessary verification tests, Yonhap said.

SOURCE: bit.ly/nBG2zO Genesis, online May 31, 2011.

http://onlinelibrary.wiley.com/doi/10.1002/dvg.20772/abstract;jsessionid=64C222081129BBFD4AB3E90C01A5CD03.d03t01