Genetically Modified Monkeys: Progress or a Step Too Far?
While much of the media coverage about the new GM monkeys is revelling in the prospects of cures for Parkinson’s disease, motor neuron disease and other devastating disorders, very little space is being given over to the vast ethical and welfare issues surrounding this development. Neither are the associated scientific/methodological problems being addressed that need to be considered before the establishment of GM primate breeding colonies can even be conceived as plausible.
Perhaps the most problematic factor is that, in this protocol, the genes insert into random sites on the target DNA, and this could result in unforeseen functional, anatomical or cognitive mutations with serious welfare implications for the animals. Until targeted insertions can be made, it is also difficult to envisage how this could be used to study specific diseases that affect specific systems and areas of the body. Furthermore, unless the insertion sites and consequences of insertion are fully characterised, each animal may potentially suffer harm before any changes are obvious to the researcher. However, given that age is often important in when genes become active and cause many human diseases, and that some genes cause rapid onset of disease-like symptoms in young animals or, indeed, cause miscarriage, being able to turn the inserted genes on and off (inducible gene expression) is desirable.
Before claiming that this will lead to more relevant models of human disorders, it must be considered that evolutionary similarity to humans does not immediately equate to biological correlation. It is highlighted that mice engineered to express human disease genes do not always develop the typical symptoms of those diseases, so will this also be the case in primates, where the ethical and welfare consequences of failure are perceived as more severe?
Moreover, the common marmoset is listed under CITES Appendix II, which means that trading them has to be strictly regulated to prevent them from becoming in danger of extinction. This may limit the sharing of data and the movement of GM animals. Containment would have to be to be relatively high, as there must not be any opportunity for defective genes to enter wild population gene pools. It also raises the question of how will breeding colonies be maintained. Will excess animals be produced to keep lines going or is cryopreservation an option, and if so, how will movement of frozen gametes be affected by transportation regulations?
The technique described in this research is relatively efficient and does strongly suggest the possibility of breeding GM marmosets rather than having to create them from scratch each time. While this would be desirable if it avoids additional experimental procedures for the animals that are used, it is important to discuss not only colony maintenance as outlined above, but more importantly the long-term fate of these animals which can live for upward of 10 years and may continue to suffer from the effects of the inserted disease genes.
Science is moving at a speed with which laws, ethics and society are finding it difficult to keep pace. Each year, research in animals raises the hopes of patients around the world. Often these claims are not realised. Instead, many millions of animals, a large proportion of which have been genetically-modified, are created, only to be shelved at a later date. For this reason, it is imperative that the societal value, welfare implications and ethics of developing and using GM primates in research and testing, be thoroughly debated. After all, just because science can does not mean that it should.
Archived June 10 2009