Select Committee on Science and Technology Written Evidence



Explanation of this Research

  In terms of the impact of these proposals on research in the UK, we feel it is very important that the debate uses correct terminology. Animal eggs are used to create cloned human embryos as lab models to study disease.

  A rabbit or cow egg is taken and almost all genetic info removed (all except the mitochondrial DNA). Concurrently a patient with the disease being studied, for example Alzheimer's or motor neurone disease, has a skin cell removed. The nucleus of the patient's cell, which contains the genetic material, is put into the "empty" animal egg. An electric current is then used to trick the egg containing the human genetic material into dividing to become an early embryo (genetically the embryo will be 99.5% human). Stem cells are extracted from the embryo and are studied for no more than 14 days to understand how cells from a patient with a disease differ from those without disease. The embryo is then destroyed.

Are these chimeric embryos? Or, are they hybrid embryos?

  No and no. A chimeric embryo has separate cells from two different species. A hybrid embryo genetic material from two different species—i.e. the egg and sperm cells are from different species.

  The cells produced in this research contain more than 99.5% human DNA, the remainder being mitochondrial DNA from the animal cell. A more specialised term for these embryos could be "mammalian incubated human nuclear embryos".

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