Anthony Cox on how fear of chimeras in interfering with a rational assessment of DNA research. (NB: This article was first published in Spring 2007.)

chimera200When H G Wells wrote The Island of Doctor Moreau, the British scientific community was embroiled in a debate about vivisection. His novel played on those contemporary concerns, with Moreau’s animal victims transmogrified into humanlike monsters. When film producers revisited the story in 1996, Marlon Brando’s Dr Moreau had moved with the times, tampering with his animals’ DNA in order to create his creatures. In the past few weeks, a controversy about so-called “Frankenbunnies” has sparked a new debate about the relatively uncharted ethics surrounding genetic science.

The revolution in genetic science came to wider public attention after the cloning of Dolly the sheep in 1996, but has yet to deliver tangible benefits to the public. However, some researchers believe that the key to understanding the pathology of degenerative diseases, and eventually finding potential cures, lies with embryonic stem cell research. It is suggested that the research may help future sufferers of conditions like Alzheimer’s disease, Parkinson’s disease, cystic fibrosis, motor neurone disease and Huntington’s disease.

It is the nature of this research that has sparked a public debate about ethics in genetic research. Human embryos are in short supply, and there are obvious ethical concerns about experimenting on fertilised human embryos. For this reason, scientists have focused on ways to create stocks of similar embryos using non-embryonic human genetic material in animal embryo structures. Animal embryos are readily available as a by-product of the food industry.

In brief, the animal embryo (rabbit or cow) is cleared of its resident genetic material, and human genetic material is inserted. The resultant embryo is 99.9% human, with a residual amount of genetic material remaining in the cell structure making up the remainder. The resultant egg is stimulated to create stem cells for research. After the stem cells are extracted, and before it reaches 14 days of age, the embryo is destroyed. These embryos are called human-to-animal hybrids, or cybrids – a term considered more accurate by scientists in the field, since it avoids the suggestion that a true hybrid organism is being created: only 0.1% of the embryo would be animal, only a few cells would be created, and there is no intent to produce a viable foetus which would become a hybrid “animal”.

Despite the UK government’s generally positive views on stem cell research, in stark contrast to the debate in the United States, they initially blanched at the idea of human-to-animal hybrids. In the process of updating the sixteen-year-old Human Fertilisation and Embryology Act, the government produced a White Paper in December 2006, which appeared to propose outlawing research using “hybrid embryos”.

This aversion sprang from what the government termed “considerable public unease with the possible creation of embryos combining human and animal material”. The considerable public unease appeared to consist of a number of responses to a Human Fertilisation and Embryology Authority (HFEA) consultation, which had only briefly considered the ethical issues concerning cybrids. Critics of the White paper, such as the Liberal Democrat MP Evan Harris, argued that the consultation gave a misleading impression of the strength of opposition and was more reflective of a well-organised lobby against such research, rather than widespread public opposition. In addition, those involved in this form of embryonic research submitted a joint statement to the consultation process, thus diminishing their impact to one voice amongst seemingly many.

Neither were signals from government sources re-assuring for the scientists involved, with a Department of Health spokesman stating that “previous research in this area shows ongoing and widespread support for a ban on creating human-animal hybrids and chimeras for research purposes” However, despite such initial statements, under questioning Prime minister Tony Blair noted that “If there’s research that’s going to help people then we want to see it go forward.”

By the time the HFEA was due to deliver its widely expected rejection to two applications for research involving cybrids, the mood had changed. HFEA noted that cybrids would potentially fall within their remit to regulate and licence and that such research was not prohibited by current legislation, and argued for a full and proper debate on the issue of cybrids.

So what are some of the key issues? One issue is the “Yuck” factor: an almost instinctive hostility to the mixing of species. One of the opponents of cybrids research, Josephine Quintavalle from CORE ethics, has suggested this has made the anti-cybrid argument easier to make: “There’s the Yuck factor. There is an innate repugnance that we would mix the species in this way.” Even the UK scientific community, perhaps pragmatically, accepts the strength of this feeling, since they have a self-imposed ban on the injection of human stem cells into developing embryos of another species.

One explanation put forward for the Yuck factor by ethicists is that the creation of interspecies creatures evokes the same feelings as bestiality, widely considered immoral, and some may see the erotic mixing of species to be directly analogous to biotechnological mixing. Another, perhaps more plausible, explanation however lies in the concepts of boundaries that humans create to order their world, and the taboos that operate to avoid mixing items from distinct categories. By being neither human nor animal, cybrids threaten such social and moral concepts and boundaries – which are what set mankind apart from other creatures. They become an abomination and threaten our human identity. Andrew Ferguson from the Christian fellowship puts it thus: “We are creating a being that is not completely human. We should not alter the whole future of what it means to be human. We should not blur the distinction that’s been there in nature since the dawn of time”

What is the nature of the cybrids produced? If they are 99.9% human, and 0.1% animal, then are they part animal and part-human, or do we have to place them within one category? This is important, since some argue that the human-to-animal hybrids that are created have rights in themselves – rights we would generally apply only to those in the human camp. Andrew Ferguson argues that 99%-human embryos should be considered human, and therefore that the ending of such a life to obtain stem cells is unethical. In the case of a debate about the nature of the embryo, he claims “we should give him or her the benefit of the doubt”. Paradoxically, the stress that pro-cybrid researchers put on minimizing the animal genetic content of the embryo, presumably in order to reduce the Yuck factor, actually strengthens this argument. Dr Calum MacKellar of the Scottish Council on Scottish Bioethics has also stated that a animal-human embryo is “not just a pile of cells, but [has] a special moral status as a human person.”

The counter-argument to this is that the raising of cybrid embryos into human persons with rights is emotive and that the cybrids are purely created with the intent of harvesting stem cells. They are not intended to be viable embryos for the creation of an organism, nor have they been created from viable human embryos.

Concern about crossing interspecies boundaries in other ways is less problematic. Previous animal hybrid work has produced such cross-species creatures as the geep (a cross between a sheep and a goat), and the public have been largely unconcerned by the sight of a mouse with a human ear grown on its back, or for that matter medical xenotranplantation, The use of replacement pig heart valves in those with heart valve defects is now routine, and not generally opposed by those who are concerned about cybrid research. However, none of these examples threaten our understanding of human identity, or raise issues of new moral obligations.

Another ethical issue is the value of such research to human health. In the debate following the potential HFEA ban, both the Medical Research Council and the Wellcome Trust have backed the validity of cybrid research, suggesting it offers the possibility of significant improvements in the treatment of disease. A group of more than 40 leading UK doctors, scientists, ethicists, and politicians wrote to The Times on the 10th of January 2007 arguing that there were “clear potential benefits to human health” from this line of research. Opponents are less sure that such benefits will accrue.

Stephen Minger, director of the stem cell biology laboratory at King’s College London, is optimistic that the consultation would give scientists the opportunity to explain the underlying science and why the development of animal-human hybrids for stem cell research regulated by the authority is essential. Researchers are also not opposed to greater regulation in this field, as it is currently a regulatory void; they welcome an informed debate.

Despite the Frankenbunny headlines, the debate appears to have moved in favour of those who think such research is warranted. David King, the Government’s chief scientific adviser, argued that such research should be allowed under tight control; when put under pressure at the Parliamentary Science Committee, Caroline Flint, Minister of State for Public Health, suggested that her department’s position had been misrepresented. Acknowledging the changing climate she stated, “What is emerging now—which I think is positive—is possibly far more science engagement on this issue and more ideas and evidence coming forward as to developments than was provided at the time of the consultation.”

Antony Cox is a pharmacovigilance pharmacist who works at the West Midlands Centre for Adverse Drug Reactions, and also as a tutor at Aston University’s School of Pharmacy. He blogs at Black Triangle

  1. A bit of an unfortunate terminological collision; I was expecting this to be about the other sort of genetic chimera.

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