http://www.guardian.co.uk/medicine/stor ... 55,00.html
The government has overturned its proposed ban on the creation of human-animal embryos and now wants to allow them to be used to develop new treatments for incurable diseases such as Parkinson's and Alzheimer's.
The proposal, in a new draft fertility bill published today, would allow scientists to create three different types of hybrid embryos.
Scientists would be allowed to grow the embryos in a lab for no more than two weeks, and it would be illegal to implant them in a human.
The first kind of hybrid allowed under the bill, known as a chimeric embryo, is made by injecting cells from an animal into a human embryo. The second, known as a human transgenic embryo, involves injecting animal DNA into a human embryo.
The third, known as a cytoplasmic hybrid, is created by transferring the nuclei of human cells, such as skin cells, into animal eggs from which almost all the genetic material has been removed.
This is this type of human-animal embryo that is being developed in British universities. Scientists say that developing these embryos will provide a plentiful source of stem cells - immature cells that can develop into many different types of tissue - for use in medical research.
The move is a U-turn on proposals to outlaw all types of human-animal embryos set out by ministers in a white paper published last December.
But the new proposal would not allow the creation of "true hybrid" embryos, which would involve fertilising a human egg with animal sperm or vice versa.