Tracing Dolly – How to Find Clones Using DNA
Tracing Dolly – How to Find Clones Using DNA
Date: 15 February 2008
Trinity College Dublin and Chief Scientific Adviser to the Government of IrelandAfter much study of the literature, the US Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) have concluded that cloned animals and their offspring pose no additional challenges to human health.
Still, some people have reservations. There are concerns about animal welfare. There are considerable abnormalities during pregnancy, leading to high wastage. Success rates are less than 10%. This means that clones are costly: more than $10,000 each in the case of cattle. And there are also fears that clones could lead to disruption to domestic markets and more particularly to objections from more sensitive markets like Japan and Europe.
For a complex of these reasons, the USDA has asked that clones be kept out of the food chain at the moment while the Agency’s Economic Research Service studies these very issues as requested by Congress.
Since clones have been declared safe by the FDA, products from cloned animals would not need to be labelled as such. However, if some producer group, packer or retailer wished to label their products clone-free, the law would require them to back up that label claim with credible evidence that it was true.
Advances in genetic technology have made cloning possible, and have in parallel provided a convenient way of providing such a back-up. The technology is called DNA traceability.
Developed initially in response to the BSE (mad cow) crisis in Europe in the 1990s, it provides an unchallengeable link between the product and the animal. A tiny (pinhead sized) piece of tissue is taken from the live animal or more usually from the carcass. A DNA profile is created and stored in a computer.
The beef carcass is processed ultimately into as many as a thousand separate retail pieces or cuts. These may end up on consumers’ plates across a dozen states and over several weeks. Any such piece of meat can be sampled to give a DNA profile, which can be checked instantly against those on the computer file, and the animal of origin can be identified. This can be done without the need for a costly (and corruptible) proliferation of paper and bar-codes. The cost of the DNA system is pennies per pound.
DNA traceback is used by retailers in Europe to independently verify claims about country of origin, farm of origin, breed, organic etc.
Using this system to back up claims of clone-free would be even simpler. It would start with a DNA profile of the clone. It would, however, require that a DNA profile of every clone should be available. Once the DNA database of clones is established, a sampling and profiling programme could be applied to any supply chain to verify whether any clones are present.
Tracing Dolly – How to Find Clones Using DNA