Modern Chimeras: Down on the Organ Farm, or Marooned on the Island of Dr. Moreau?
By David Prentice, PhD | September 08, 2016
by David Prentice, PhD
If you’ve never read the H.G. Wells novel The Island of Dr. Moreau nor seen the movie adaptation (the 1996 version starred Marlon Brando as the scientist), you might want to take the next opportunity to do so. The story of a doctor who creates human-animal chimeras (mixtures of different species) is fiction, but the National Institutes of Health (NIH) is proposing to move the story toward reality. NIH has proposed to loosen prohibitions on laboratory creation of human-animal chimeras as well as allow taxpayer funding for the experiments. While public comments were solicited (the comment period has now ended), the indications are that approval of the proposals is a foregone conclusion (one NIH official enthused that they hoped to have the new funding regulations in place in time for this December’s grant review round.)
What may be surprising to many is that this human-animal chimera research is already taking place, including gestation of these chimeras on research farms. News reports list at least three U.S. laboratories where attempts at growing chimeras that mix farm animals with humans are occurring now. Supposedly none of the chimeras have yet been brought to birth—one lab claims to stop the experiments at 28 days of gestation, another lab apparently stops at 60 days gestation—but the desire of the scientists is to birth and mature these creatures. And also to get lots of money from large NIH grants. Current funding for such projects has come from small private grants and the California stem cell program, but only NIH provides the premier high-dollar grants.
It is not the simple mixing of human cells with animals that is the problem. Some chimeras meet both ethical and scientific tests for validity. Examples include transplantation of pig heart valves into humans, or versions of the “oncomouse” which contain human genes for study of cancer, or other types of transgenic animals such as mice that contain the human insulin gene for study. Mice with human livers have previously been developed; the human liver cells are transplanted into born mice and have provided excellent models to study liver disease. These and many other transgenic as well as human-to-animal cell transplant experiments do not actually create concern because these chimeras do not muddle species identity, abrogate human dignity or create animals with an ambiguous moral value or human consciousness.
But the current proposals for human-animal chimeras do purposefully propose crossing ethical barriers and are based on questionable science. One proposal for creation of human-animal chimeras is for generation of human transplantable organs. The human-animal chimeras in question are created by injecting human stem cells into young animal embryos only a few days old. The embryos are then transferred to the wombs of female livestock for gestation. In theory, genetically engineered animal embryos would be used, with genetic knock-outs that preclude formation of certain organs, e.g., liver—the added human stem cells would “fill the gap,” creating a human-derived organ in place of the missing animal organ. Using farm animals would be necessary to produce large enough human organs for transplant.
Others propose creating human-animal chimeras that would allow the human cells to contribute to the brain or produce human gametes within an animal’s body. Again, the addition of the human cells to the animal embryo occurs so early in development that the human cells could form virtually any tissue. What could go wrong with NIH’s plan to fund chimera experiments? Plenty. What is the moral status of an animal with a human brain? What could happen if two animals producing human gametes breed and gestate a human? What other aspects of humanity could be breached and sow ethical confusion? Would an animal with human arms or a human face be problematic? Could construction of some chimeras under these proposals actually lead to creation of human embryos (which would violate federal statute)? Do we need to re-examine the question: “What is man, that thou art mindful of him?” (Psalm 8:4a, KJV).
Scientifically valid, ethically framed alternatives exist to assist the development of basic science as well as clinical medicine. There is no scientific or ethical necessity that validates NIH approval or taxpayer funding of experiments creating these proposed human-animal chimeras.
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