The Niche

Brits report making hybrid cow-human embryo

Newcastle University says researchers led by Lyle Armstrong have made hybrid embryos containing material from cows and humans. The announcement comes just as the government gears up on whether or not the creation of such embryos should be legal. Newcastle University, which already had approval for the research from UK regulatory authorities, decided to push forward so the research would not risk being stalled by an upcoming vote in the House of Commons, reports the BBC.

The embryos lived for three days, and were not used to make embryonic stem cells, according to that report. They were made by putting human DNA into cow eggs after the cow chromosomes had been removed. Scientists argue that such procedures are valuable both to understand how embryos develop, to develop better techniques for making embryonic stem cell lines, and to develop more useful embryonic stem cells. The hybrid embryos cannot, by law, be allowed to develop for more than two weeks, when some precursors of nerve tissue develops. The first reported human-animal chimeras combined human nuclei with rabbit eggs; other chimeric animals have been made as well. Here’s an old summary. Here’s a newer one.

See Nature Reports Stem Cells commentary on a scientific argument for chimeras by Ian Wilmut , a theological argument for chimeras by Ted Peters, and an argument against creating and destroying embryos for research by Markus Grompe. We also summarized the UK Academy of Medical Sciences’ report on this issue.

The UK press has been roiling with accusations by the Catholic Church that the work is monstrous. Scientists have responded that the Church is misrepresenting the science and have offered to meet with religious officials. For a recent example, see the New Stateman.

Newcastle has a history of dramatically announcing accomplishments before work appears in the peer-reviewed literature. In February, they announced the creation of embryos using material from three people. See Erika Check Hayden’s article in Nature News.

The Science Media Centre has already released statements of scientists’ responding to the news, all saying that they lack data to assess research. Here are those statements:

Martin Bobrow, Emeritus Professor of Medical Genetics, Cambridge, said:

“I have no idea whether this is true or not but Dr Armstrong has been working towards this for a long time and has recently been given a license to pursue this research. It would be unsurprising if he did not have early data but it is very unhelpful to speculate about how significant they are until we have more facts.

“If it turns out to be true that he has so rapidly been able to create an embryo that could produce a medically useful stem cell line, then that would be a very strong argument for pursuing that particular technique.”

Peter W. Andrews, Professor of Biomedical Science, Centre for Stem Cell Biology, University of Sheffield, said:

“The production of embryos by transferring the nucleus of an adult human cell to a human egg from which its own nucleus has already proved very difficult, let alone by combining a human nucleus with an animal egg. Apparently these researchers have achieved some success, but by using the nucleus from a very early embryonic cell, which might be easier to reprogram than an adult cell.

However, at the moment it is impossible to assess the significance of this report until we know more details of what has been achieved, the results have been repeated and, importantly, they have been reviewed by independent researchers in the usual way.”

Prof Colin Blakemore, former Head of the Medical Research Council, said:

“The creation of hybrid embryos is not illegal and researchers in Newcastle and London were granted provisional licences for such research in January, after an extensive consultation by the HFEA. This research is at a very early stage and no results have been peer-reviewed or published. However, these preliminary reports give hope that this approach is likely to provide stem cells for research without the use of human eggs or normal human embryos. The new Bill is intended to confirm the arrangements for regulation of this important area of research.”

Dr Mark Walport, Director of the Wellcome Trust, said:

“It is too early to assess the significance of these results but this is an important area of science that has been scrutinised by the HFEA. The aim of the research is to advance human health. This work emphasises the importance of the parliamentary scrutiny of this area of research over the coming weeks.”


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