Ethics of Stem Cell Research – Developing a Cross between Species
The idea of a chimera, a cross between species, has been around since the mythological creatures of ancient Greece, such as the centaur (a man’s torso with a horses body) and the griffin (the wings, head, and claws of an eagle and the body of a lion). Today, due to our advances in biotechnology, we are seeing this mythology become a reality, but in a different respect. Human-nonhuman animal chimeras are being developed by injecting animal blastocysts with human embryonic stem cells. The cells need to be injected at the right point in development, after the body plan of the animal has formed and before the immune system develops. It is done at this time to avoid deforming the animal and so the fetus does not reject the cells. In some studies, the resulting animal embryo had a mixture of animal cells, human cells, and a hybrid of the two different types of cells. The hybrid cells contained both human and animal genes (Vince, 2004). These chimeric embryos have been developed in such animals as mice, pigs, rabbits, and chimpanzees (Vince, 2004; Glenn, 2003).
There are great potential benefits of these findings. The pig chimera was modified with the intent that the human DNA present in the cells would aid in the success rate of xenotransplantation. The chimeras could also provide more accurate animal models for research.
With all the good that may be on the way with the present findings, the ethical issues and potential for abuse of this knowledge is both heavy on the heads of scientists. In the 1998 article by Rick Weiss, the “human-animal chimera” seems off limits, however the research is now well underway. The article was published in the Washington Post and shows how we have strayed from our original intent:
“In an unusual move applauded by ethicists and government officials, the university association holding patent rights to Thomson's cells said that anyone wishing...