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handy for walks after dark but are their "deposits" flourescent ? :) Quoting rayilynlee <[log in to unmask]>: > Fluorescent puppy is world's first transgenic dog > a.. 12:00 23 April 2009 by Ewen Callaway > b.. For similar stories, visit the GM Organisms and Genetics Topic Guides > A cloned beagle named Ruppy - short for Ruby Puppy - is the world's first > transgenic dog. She and four other beagles all produce a fluorescent protein > that glows red under ultraviolet light. > > A team led by Byeong-Chun Lee of Seoul National University in South Korea > created the dogs by cloning fibroblast cells that express a red fluorescent > gene produced by sea anemones. > > Lee and stem cell researcher Woo Suk Hwang were part of a team that created > the first cloned dog, Snuppy, in 2005. Much of Hwang's work on human cells > turned out to be fraudulent, but Snuppy was not, an investigation later > concluded. > > This new proof-of-principle experiment should open the door for transgenic > dog models of human disease, says team member CheMyong Ko of the University > of Kentucky in Lexington. "The next step for us is to generate a true disease > model," he says. > > However, other researchers who study domestic dogs as stand-ins for human > disease are less certain that transgenic dogs will become widespread in > research. > > Dogs already serve as models for diseases such as narcolepsy, certain cancers > and blindness. And a dog genome sequence has made the animals an even more > useful model by quickening the search for disease-causing genes. Most dog > genetics researchers limit their work to gene scans of DNA collected from > hundreds of pet owners. > > Making a glowing dog > Lee's team created Ruppy by first infecting dog fibroblast cells with a virus > that inserted the fluorescent gene into a cell's nucleus. They then > transferred the fibroblast's nucleus to another dog's egg cell, with its > nucleus removed. After a week dividing in a Petri dish, researchers implanted > the cloned embryo into a surrogate mother. > > Starting with 344 embryos implanted into 20 dogs, Lee's team ended up with > seven pregnancies. One fetus died about half way through term, while an > 11-week-old puppy died of pneumonia after its mother accidentally bit its > chest. Five dogs are alive, healthy and starting to spawn their own > fluorescent puppies, Ko says. > > Besides the low efficiency of cloning - just 1.7 per cent of embryos came to > term - another challenge to creating transgenic dogs is controlling where in > the nuclear DNA a foreign gene lands. Lee's team used a retrovirus to > transfer the fluorescent gene to dog fibroblast cells, but they could not > control where the virus inserted the gene. > > This would seem to prevent researchers from making dog "knockouts" lacking a > specific gene or engineering dogs that produce mutant forms of a gene. These > knockout procedures are now commonly done in mice and rats, and three > researchers earned a Nobel prize in 2007 for developing this method, called > "gene targeting". > > No bright future? > Ko is working to adapt a procedure used so far in pigs, cows and other > animals to target genes in cloned dogs. His lab hopes to knock out a specific > oestrogen receptor in dogs to understand the hormone's effects on fertility. > > The long lifespan of dogs and their reproductive cycle could make them more > relevant to human fertility than mice, he says. "I think these dogs will be a > very useful model for our research." > > Greg Barsh, a geneticist at Stanford University who studies dogs as models of > human disease, says creating a transgenic dog is "an important > accomplishment", showing that cloning and transgenesis can be applied to a > wide range of mammals. > > "I do not know of specific situations where the ability to produce transgenic > dogs represents an immediate experimental opportunity," Barsh adds. But > transgenic dogs will give researchers another potential tool to understand > disease. > > However, Nathan Sutter, a geneticist specialising in dogs at Cornell > University in Ithaca, New York, says "transgenesis is labourious, expensive > and slow". > > Add the expense of caring for laboratory-reared dogs and negative public > perceptions and it could mean few researchers turn to transgenic dogs like > Ruppy, he says: "it's not on my horizon as a dog geneticist at all." > > Journal reference: genesis (DOI: 10.1002/dvg.20504) > > If you would like to reuse any content from New Scientist, either in print or > online, please contact the syndication department first for permission. New > Scientist does not own rights to photos, but there are a variety of licensing > options available for use of articles and graphics we own the copyright to. > > Rayilyn Brown > Director AZNPF > Arizona Chapter National Parkinson Foundation > [log in to unmask] > > ---------------------------------------------------------------------- > To sign-off Parkinsn send a message to: mailto:[log in to unmask] > In the body of the message put: signoff parkinsn ---------------------------------------------- This mail sent through http://www.ukonline.net ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn