It was recently announced that scientists have been able to engineer rabbits that glow green under a particular light, a move they hail as a breakthrough for fighting disease. Why has this got scientists excited and why are there pressing ethical problems to consider?
Researchers from Hawaii and Turkey have, in a joint effort, used cloned embryos to produce a litter of eight infant rabbits, but two of the litter carried a little genetic secret. These so-called transgenic rabbits appear entirely normal under every day conditions. However, when exposed to a particular kind of blue light, they glow bright green. This was achieved by injecting a fluorescent protein derived from jellyfish into the rabbit embryos in the lab.
While the animals feel no ill effects of this change, and while in and of itself it might seem a rather gaudy display of scientific skill, it is meant to serve a larger purpose. The latent green shine is not the important part. It is the fact that, as indicated by the green fluorescence, the genetic material taken from a jellyfish and implanted into the rabbit is functioning as it should.
“It’s just a marker to show that we can take a gene that was not originally in the animal and now exists in the animal,” researcher Dr. Stefen Moisyadi, Associate Professor at the University of Hawaii Institute for Biogenesis Research and chief researcher.
If this technique sounds familiar, that’s because it has already been tried with a number of other animals (and a number of fluorescent genes taken from different animals) dating back to the 1980s. Those animals include but are not limited to lab mice, kittens, piglets, and reportedly even a monkey.
The use of Green Fluorescent Protein (GFP) as a tag to ensure that in genetic tests the right tissue was targeted is of itself noncontroversial. The aim of this latest research, though, wades into more troubled waters.
The first aim is to gradually improve uptake of the gene in the host animals, or to put it more plainly to yield litters where, eventually, all the animals demonstrate GFP. That’s because the current uptake is quite low but techniques are improving.
Once this is achieved, the researchers will then be able to apply their techniques to adding more useful genes to animals that, in the future, could allow them to use these transgenic animals to produce proteins, usually expressed through their milk but sometimes through their plasma, semen or other bodily fluids, that can then be refined into low-cost pharmaceuticals. In theory, this would allow us to treat a range of disease and disorders for a much lower cost than is currently attached to our medicines.
This kind of engineering has already been achieved in several areas and is built on a process that is not at all new. A concrete example can be found as far back as the 1920s, when researchers first extracted insulin from a pig pancreas. However, one modern and seemingly innocuous application can be found in what have come to be called Enviropigs.
Canadian company TGN Biotech produced groups (or, in testing parlance, lines) of Yorkshire pigs that are engineered to digest inorganic phosphates from their feed in a more effective manner than regular pigs. This in turn means the pigs produce fecal waste that is less toxic when turned into manure.
While scientifically this was an ingenious way of solving the problem, animal rights advocates have pointed out that had the pigs not been suffering such disgusting conditions as a result of factory farming, there would have been no need for this extraordinary intervention.
In the same way, the use of transgenic animals for producing medicines comes with a host of very particular ethical concerns. Yet, the general public may be surprised to hear that there are drugs on the market that are the product of just this process.
In 2006, the therapeutic protein ATryn was approved by the Food and Drug Administration (FDA) of the United States. This product is used as a coagulant for those who need surgery but suffer from a rare clotting disorder. It was produced from the milk of transgenic goats.
There were several objections raised to this process. In particular, the Humane Society of the United States is quoted as saying that the process and manufacture of the aforementioned drug was “a mechanistic use of animals that seems to perpetuate the notion of their being merely tools for human use rather than sentient creatures.”
Knowing the controversy that surrounds this kind of procedure, Dr. Moisyadi has offered the following defense:
The final goal is to develop animals that act as barrier reactives to produce beneficial molecules in their milk that can be cheaply extracted, especially in countries that can not afford big pharma plants that make drugs, that usually cost $1bn to build, and be able to produce their own protein-based medication in animals. To the people against, I say: think about, what are the benefits and what are the injuries? And if the benefits outweigh the injuries, let’s go with the benefits.
To many animal welfare and animal liberation advocates, this would seem a somewhat trite attempt at appeasement that disregards animal suffering and the treatment of animals as property for the purpose of human benefit.
Certainly, we can accept that the animals may not be harmed directly by having their genetic makeup changed, in much the same way that an objection to GM plants or animals simply because they are GM is facile. At the same time, we can express serious ethical concerns that this continues the use of animals in animal testing (indeed, adding to the already established practice of using transgenic animals as disease models) as though such concerns are irrelevant. They are not.
Still, this kind of research is set to continue and now scientists are waiting on the first new line of transgenic lambs. Those lambs will be born in November.
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