Chimera Ebryos to experiment on, but not implant
Hybrid embryos get go-aheadDavid BattyThursday May 17, 2007
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.
The government was criticised by the Commons science and technology
committee for proposing an outright ban after objections were raised by pro-life
groups opposed to any research on embryos.
The draft bill, which also covers fertility treatment, will overhaul the
Human Fertilisation and Embryology Act 1990.
British scientists have already applied to the Human Fertilisation and
Embryology Authority, which regulates embryo research, for a licence to use
human-animal embryos for medical research.
Professor John Burn, head of the human genetics institute at Newcastle
University, welcomed the government's U-turn.
"I'm delighted that common sense has prevailed. I fully understand the
knee-jerk reaction that creating human-animal embryos is worrying," he
"But what we're talking about here are cells on a dish not a foetus. We're
talking about something that looks like sago under the microscope. And it's
illegal to ever turn these cells into a living being."
A team led by Lyle Armstrong at Newcastle University's stem cell institute
has applied to the HFEA to use cow eggs to develop stem cells for the treatment
of diabetes and spinal paralysis.
Another team led by Professor Stephen
Minger, director of the stem cell biology laboratory at King's College London,
wants to use human-bovine embryos to study degenerative neurological diseases
such as Parkinson's and Alzheimer's.