Rabbit Advocacy Animal Matters


Clone team want to grow human cells in rabbit eggs

January 13, 2005 Julie Wheldon - Daily Mail

British scientists want to create embryos by combining rabbit eggs with human DNA, it has emerged. They hope the controversial move will boost stem cell research into incurable diseases by giving them a plentiful supply of eggs on which to hone their skills.

The scientists claim the development is needed as current human egg shortages are likely to worsen following a recent cloning scandal in which Korean research was exposed as fake. However, ethical campaigners last night called the idea "repugnant" and "very disturbing".

A team led by Professor Ian Wilmut - the pioneer behind Dolly the Sheep, the first mammal cloned from an adult cell - is currently trying to use stem cells from embryos to learn more about the triggers for motor neurone disease.

Stem cells are building blocks that can turn into any part of the body. The team plans to turn them into nerve tissue, so scientists can then study how disease develops in the laboratory. Until now Professor Wilmut, of Edinburgh University, and his team have been relying on donations of human eggs to try to harvest the stem cells. However, they cannot get enough as the procedure is not without risks to women.

They are now in discussion with the Human Fertilisation and Embryology Authority, which regulates embryo research, about using rabbit eggs instead.

The plan was revealed by one of Professor Wilmut's research colleagues. Professor Chris Shaw, from King's College London, said they hoped to take a rabbit egg, remove its genetic material and replace it with human DNA.

Stimulated egg

The egg would then be stimulated to turn into an embryo, from which they could harvest stem cells. The ultimate aim is to be able to grow several motor neurone disease stem cell lines - banks from which limitless supplies can be obtained - so they can study how the condition develops.

It is not entirely clear how the research would be covered by existing laws. The embryo would have only human genetic information inside, but rabbit proteins would still be present.

And because the impact of these proteins is not yet known, it would not be considered a true clone - even though it would contain just one person's DNA and be created through standard cloning methods.

The HFEA said because the embryo would be virtually indistinguishable from a human embryo, the researchers would need to apply for a licence and prove the research is "necessary and desirable". And because it began life as an animal-human hybrid, the embryo would have to be destroyed by the time it was 14 days old and could never be implanted into a woman and allowed to grow.

Professor Shaw said there was an increased need to get eggs from an alternative source because he expects donations to plummet after the scandal in South Korea.

Professor Hwang Woo-Suk claimed he had created cloned human embryos and 11 sets of stem cells tailor-made to patients. This week an investigation concluded both pieces of research were fabricated.

Professor Shaw said: "People's emotional response to this scandal may be to decide not to engage with the research."

Josephine Quintavalle, of Comment on Reproductive Ethics, said most people would find the proposed research repugnant. "It would create something profoundly abnormal," she said. "It is so perverse and I cannot believe that such a convoluted way is necessary to perfect stem cell technology."

Similar research has been done in China, and animal cells have been used in fertility research. However this research, with its combination of cloning, stem cells, animal eggs and human DNA, would be the first of its kind in Britain. 

Animal-Human Hybrids Spark Controversy 

January 25, 2005 Maryann Mott - National Geographic News 

Scientists have begun blurring the line between human and animal by producing chimeras—a hybrid creature that's part human, part animal.

Chinese scientists at the Shanghai Second Medical University in 2003 successfully fused human cells with rabbit eggs. The embryos were reportedly the first human-animal chimeras successfully created. They were allowed to develop for several days in a laboratory dish before the scientists destroyed the embryos to harvest their stem cells.

In Minnesota last year researchers at the Mayo Clinic created pigs with human blood flowing through their bodies.
And at Stanford University in California an experiment might be done later this year to create mice with human brains.

Scientists feel that, the more humanlike the animal, the better research model it makes for testing drugs or possibly growing "spare parts," such as livers, to transplant into humans. Watching how human cells mature and interact in a living creature may also lead to the discoveries of new medical treatments.

But creating human-animal chimeras—named after a monster in Greek mythology that had a lion's head, goat's body, and serpent's tail—has raised troubling questions: What new subhuman combination should be produced and for what purpose? At what point would it be considered human? And what rights, if any, should it have?

There are currently no U.S. federal laws that address these issues.

Ethical Guidelines

The National Academy of Sciences, which advises the U.S. government, has been studying the issue. In March it plans to present voluntary ethical guidelines for researchers. A chimera is a mixture of two or more species in one body. Not all are considered troubling, though.

For example, faulty human heart valves are routinely replaced with ones taken from cows and pigs. The surgery—which makes the recipient a human-animal chimera—is widely accepted. And for years scientists have added human genes to bacteria and farm animals.

What's caused the uproar is the mixing of human stem cells with embryonic animals to create new species.

Biotechnology activist Jeremy Rifkin is opposed to crossing species boundaries, because he believes animals have the right to exist without being tampered with or crossed with another species. He concedes that these studies would lead to some medical breakthroughs. Still, they should not be done.

"There are other ways to advance medicine and human health besides going out into the strange, brave new world of chimeric animals," Rifkin said, adding that sophisticated computer models can substitute for experimentation on live animals. "One doesn't have to be religious or into animal rights to think this doesn't make sense," he continued. "It's the scientists who want to do this. They've now gone over the edge into the pathological domain."

David Magnus, director of the Stanford Center for Biomedical Ethics at Stanford University, believes the real worry is whether or not chimeras will be put to uses that are problematic, risky, or dangerous.

Human Born to Mice Parents?

For example, an experiment that would raise concerns, he said, is genetically engineering mice to produce human sperm and eggs, then doing in vitro fertilization to produce a child whose parents are a pair of mice. "Most people would find that problematic," Magnus said, "but those uses are bizarre and not, to the best of my knowledge, anything that anybody is remotely contemplating. Most uses of chimeras are actually much more relevant to practical concerns."

Last year Canada passed the Assisted Human Reproduction Act, which bans chimeras. Specifically, it prohibits transferring a nonhuman cell into a human embryo and putting human cells into a nonhuman embryo. 

Cynthia Cohen is a member of Canada's Stem Cell Oversight Committee, which oversees research protocols to ensure they are in accordance with the new guidelines. She believes a ban should also be put into place in the U.S.

Creating chimeras, she said, by mixing human and animal gametes (sperms and eggs) or transferring reproductive cells, diminishes human dignity. "It would deny that there is something distinctive and valuable about human beings that ought to be honored and protected," said Cohen, who is also the senior research fellow at Georgetown University's Kennedy Institute of Ethics in Washington, D.C.

But, she noted, the wording on such a ban needs to be developed carefully. It shouldn't outlaw ethical and legitimate experiments—such as transferring a limited number of adult human stem cells into animal embryos in order to learn how they proliferate and grow during the prenatal period.

Irv Weissman, director of Stanford University's Institute of Cancer/Stem Cell Biology and Medicine in California, is against a ban in the United States. "Anybody who puts their own moral guidance in the way of this biomedical science, where they want to impose their will—not just be part of an argument—if that leads to a ban or moratorium. … they are stopping research that would save human lives," he said.

Mice With Human Brains

Weissman has already created mice with brains that are about one percent human. Later this year he may conduct another experiment where the mice have 100 percent human brains. This would be done, he said, by injecting human neurons into the brains of embryonic mice.

Before being born, the mice would be killed and dissected to see if the architecture of a human brain had formed. If it did, he'd look for traces of human cognitive behavior.

Weissman said he's not a mad scientist trying to create a human in an animal body. He hopes the experiment leads to a better understanding of how the brain works, which would be useful in treating diseases like Alzheimer's or Parkinson's disease. The test has not yet begun. Weissman is waiting to read the National Academy's report, due out in March.

William Cheshire, associate professor of neurology at the Mayo Clinic's Jacksonville, Florida, branch, feels that combining human and animal neurons is problematic. "This is unexplored biologic territory," he said. "Whatever moral threshold of human neural development we might choose to set as the limit for such an experiment, there would be a considerable risk of exceeding that limit before it could be recognized."

Cheshire supports research that combines human and animal cells to study cellular function. As an undergraduate he participated in research that fused human and mouse cells. But where he draws the ethical line is on research that would destroy a human embryo to obtain cells, or research that would create an organism that is partly human and partly animal.

"We must be cautious not to violate the integrity of humanity or of animal life over which we have a stewardship responsibility," said Cheshire, a member of Christian Medical and Dental Associations. "Research projects that create human-animal chimeras risk disturbing fragile ecosystems, endanger health, and affront species integrity."

Arizona bans creation of human-animal hybrids 

May 12, 2010 Sharon Seltzer, Care2

Arizona is back in the news for another controversial new law.  Only this time the law sounds like it came right out of a science fiction movie.  Effective as of July 29, 2010 it will be illegal in the state for scientists to produce or try to produce a human-animal hybrid. 

Last Friday, Governor Jan Brewer signed the new law which will prohibit any resident of Arizona from "creating or attempting to create an in vitro human embryo by any means other than fertilization of a human egg by a human sperm." The statute also makes it a crime to "knowingly destroy human embryonic stem cells during research" and makes it illegal to clone a human being. 

Although the law appears to be futuristic and a little over the top, researchers have begun to experiment on creating Chimeras -- "hybrid life forms that contain genetic material from both humans and animals."  

A story written in Frum Forum describes three separate research projects that have attempted this: 

  • In 2003, Chinese scientists took human cells and fused them into rabbit embryos, creating human-rabbit hybrids.  They developed for a few days before being destroyed. 

  • In 2005, Stanford University researchers trying to find a new treatment for Alzheimer's, injected human embryonic stem cells into the brains of mouse fetuses.  

  • In 2007, scientists at the University of Nevada, Reno developed a sheep whose cells were 15 percent human.

The concept of creating a hybrid life poses a whole array of ethical questions and that is why Rep. Nancy Barto, R-Phoenix, drafted the statute for Arizona.  She became concerned after reading how scientists in the United Kingdom put human DNA into empty cow eggs in order to create special embryonic stem cells for the research of various diseases. 

Barto explained, "It's placing some ethical boundaries around scientific research in Arizona.  This law will proactively prevent such experimentation." 

"We're drawing a protective line to say that human life is valuable and needs to be protected," she continued.  "We need to make sure that we're not going outside of that ethical boundary." 

Ironically the new law may end up protecting innocent animals from being used in Arizona laboratories for research.  And it may make people take a second look at how similar animals are to humans -- in terms of feelings and intellect. 

If research in the area continues, someone will have to decide what percentage of a species is human and what rights they have.  It also brings up issues of ownership and slavery. 

On the other hand, critics of the new law don't believe it is necessary at all because the National Academy of Sciences has set up their own guidelines on human-animal hybrid research.  These guidelines only allow the DNA from humans to be fused into the embryos of animals and not vice versa.  The implication is that only a small part of a human is being placed inside a whole animal. 

The guidelines also forbid any successful human-animal hybrid that reaches maturity from breeding. Creating human-animal hybrids is a confusing proposition.  Arizona may have made a smart decision to pass a law that sidesteps these issues.