Manuel

Type in the conten =Study questions strategy of getting stem cells by using animal eggs to clone human embryos= By MALCOLM RITTER | AP Science Writer 3:38 PM EST, February 2, 2009 NEW YORK (AP) — It may be futile to try producing stem cells by putting human DNA into cow or rabbit eggs and making hybrid cloned embryos, a strategy that triggered controversy recently in Britain, a new study says.

The animal eggs don't reprogram human DNA in the right way to generate stem cells, researchers report.

"Instead of turning on the right genes, it turns out the animal eggs actually turn them off," said senior study author Dr. Robert Lanza of Advanced Cell Technology in Worcester, Mass.

Another scientist disputed that conclusion.

The idea of using animal-human "hybrid" embryos drew fire last year in Britain as authorities pondered whether to let scientists try it. Opponents objected to mixing human and animal material and worried that such research could lead to genetically modified babies.

Hybrid embryos have been made elsewhere, but there's no widely accepted report of getting stem cells from them. Animal eggs are attractive because human ones are hard to get for research.

Scientists prize embryonic stem cells because they can develop into virtually any cell of the body. By inserting a person's DNA into an egg and growing an early embryo, scientists hope to extract stem cells that are a genetic match to that person. That would help in disease research and enable scientists to develop transplant tissue that avoids the risk of rejection.

For the new work, Lanza and colleagues put human DNA into human, cow and rabbit eggs and grew them into early embryos. In embryos from human eggs, they found that patterns of gene activity resembled those in ordinary human embryos. But with the human-animal hybrid embryos, the patterns were much different.

The work was funded by Lanza's company and several institutions collaborating on the research. It was published online Monday by the journal Cloning and Stem Cells.

"The idea that this is the nail in the coffin for hybrids is grossly overstated," declared Stephen Minger of King's College London, who has permission from British authorities to pursue making hybrid embryos.

He cited a 2008 study that reported key genes are in fact turned on in embryos made with cow eggs, although the efficiency is low. That study concluded that cow eggs could be useful if techniques to use them were further developed.

Minger suggested Lanza's team looked too early in embryonic development to see the activation.

Lanza, however, said he found the 2008 study to be unconvincing.

Minger's group is one of three that gained permission from British authorities to try using animal eggs. He said he thought stem cells from hybrid embryos should not be used for making transplant tissue for people.

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__AP medical writer Maria Cheng in London contributed to this report.__

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On the Net:

Cloning and Stem Cells: www.liebertpub.com/clo t of your new page here.

SUMMARY AND OPINION

The article "study questions strategy of getting stem cells by using animal eggs to clone human embryos" is about how a study of using this strategy has appeared in britain,and many other places but not as widely accepted as in britain. the main reason why this study is interesting is because it is harder and unethical to use and obtain human eggs.by doing this scientists hope by inserting a person's DNA and growing an early embryo they can extract exact replicas from that embryo, helping disease research and enable scientist to develop transplanrt tissue without the risk of rejection. in this time there is still alot of controversy going on about this study not only about its ethics but the relativity of this study, wether it is possible or impossible. the arguments on the ethics of these experiments is that people are afraid that these stem cells produced by the animal cells may create offspring genetically modified babies. For instance it can be possible that when these babies grow up they can be faster stronger than others, but also it can be possible that these babies can also grow up with deformities. On the scientific side of the two opposing sides is that if this is actually possible. According to Dr. Robert Lanza the animal eggs do not turn on the right genes, instead of turning on cells it actually turns off the genes. to prove this Dr. Lanza but human genes into a human egg, a rabbit egg, and a cow egg and grew them into early embryos. In the embryos of the human cell the embryo had grew normally as it ordinarily would, but the human-animal hybrid had come out differently. on the other side of this experiment is Stephen Minger who say that it is not completely impossible because the key genes are turned on, but the efficiency is still low, but was still able to conclude that cow eggs are possible for the use of tissue transplant.

In my opinion this research can be very beneficial. this can be beneficial because like certain types of cloning it can benefit people that need to have new organs transplanted, for instance if some one has a failing liver it can be possible to replace this failing liver by, also for skin transfussions and tissue transplants. this can help save millions of lives across the world. but the idea of creating a completely grown up organism that is technically part animal is an idea that is extremly frightining. Religiously i believe that it should be only up to fgod to create a new life. but in this case it mainly seems only possible to create body cells such as skin tissue cells, blood cells, and other body cells seems acceptable to create these clones. but scientifically i also belive that creating human stem cells by the use of animal eggs is far fetched. this seems far fetched to me because each animal has a different amount of chromosomes, if we are too put human genes into animal cells than the number of chromosomes would be different. this result in an organism that has the a different number of chromosomes than ordinary humans and if we wish to use these organims for transplants and other operations, and other things we would need to have the a identical number of chromosomes in the cells.