Taking into account a public ' very finely-divided' over the ethical issues of human -animal embryos, regulators from the Human Fertilization and Embryology Authority (HFEA) have given their nod for the controversial procedure.
Yet, the HFEA still maintains that scientists who wish to use these hybrids for research will need to apply individually for permission. The HFEA is claiming that its consultations have showed the public to be "at ease" with this idea when informed that it could lead to therapies for conditions such as Alzheimer's disease. By contrast, opponents vouch many would be "horrified" by such a move.
AdvertisementAccording to the scientists behind this research, merging human cell components with animal ones can create a human-animal hybrid embryo. Once the stem cells are removed, the embryos will be destroyed in 14 days.
Stem cells form the basic building blocks of human tissue and their potential of totipotency, or the ability to morph into just about any kind of organ cells or tissue, makes them the 'Holy Grail' in the quest for treating 'incurable diseases' like Parkinson's, Alzheimer's etc.
Currently, scientists use human eggs left over from fertility treatments, though they are in short supply and not always of good quality.
Swift to seize the opportunity, two teams from Kings College London and Newcastle University have already applied to the HFEA to use hybrid embryos.
It is now expected individual hearings for these two applications will be held in November with other scientists expected to follow suit.
Dr Stephen Minger, of King's College London was vocal in his appreciation of the HFEA's decision, saying it was the only ethically justifiable option if scientists were to push forward with their research.
Lyle Armstrong, of Newcastle University joined him: "This is excellent news. It is a positive outcome not just for our work but also for the progress of British science in general and we hope that this will lead to new technologies to benefit everyone.
"It does seem a little abhorrent at first analysis, but you have to understand we are using very, very little information from the cow in order to do this reprogramming idea.
"It's not our intention to create any bizarre cow-human hybrid, we want to use those cells to understand how to make human stem cells better", he added.
Says Lib Dem MP Dr Evan Harris, a member of the Commons' science and technology committee: "Our top-class researchers can now proceed with their applications to conduct this world-leading research."
Dr Tony Calland, chairman of the British Medical Association's ethics committee, is of the opinion that the research could lead to "major breakthroughs in treatments for Alzheimer's, Parkinson's and other serious diseases".
The HFEA decision has come amidst government moves to lay down regulations covering such research, as the law governing embryo research is out of date and does not cover the issue.
Though the government originally proposed banning the technique last year, it reversed its decision this year in a bill, which indicated ministers were minded to allow hybrid embryos, which were 99.9% human, and 0.1% animal.
Yet, dissenting voices abound. Says Anthony Ozimic, secretary of pro-life group the Society for the Protection of Unborn Children (SPUC):"This is not just a case of the 'yuk' factor - there are grave ethical and moral objections to this research and the way it is being promoted." Josephine Quintavalle, of the campaign group Comment on Reproductive Ethics, says the HFEA is wrong to be pushing ahead with a decision, which should be left to parliament."Using hybrid embryos has never been acceptable - it offends the dignity of humans and animals", he emphasizes.
Meanwhile, a spokeswoman for the HFEA has called the decision 'a challenging one to reach'."This is not a total green light for hybrid research, but recognition that this area of research can, with caution and careful scrutiny, be permitted", she stressed. On the other hand, she did agree that public opinion was "very finely divided" with people only supporting it if it was tightly regulated and likely to lead to medical advancements.