The issue of creating hybrid embryos for stem cell research was first raised in November 2006 when '...the HFEA received applications from two different research teams for a licence to derive stem cells from human embryos, created from animal eggs instead of human eggs' (1). A public consultation on this matter was opened in April 2007 with the report being published in October that same year (2,3). The Human Fertilisation and Embryology Authority (HFEA) took the decision that hybrid embryos could be created, were within the legal requirements and accordingly granted one year research licences to the two applicants in January this year (4). Last week, one of these teams reported preliminary data describing the first hybrid embryos to be created in the UK.
The HFEA took its decision on the basis that the resulting embryo was a 'live human embryo' and so fell within the remit of the Human Fertilisation and Embryology Act 1990. They also felt that based upon a previous court case that these hybrid embryos fell within the same genus of fact as other embryos covered by the Act and that in enacting the legislation Parliament had opted for a strict regime of control and as such no activity within this field was to be left unregulated (5).
Considering that an embryo created by somatic cell nuclear transfer using animal eggs and human DNA is a 'live human embryo' is one that may well be challenged, although if this was challenged legally I would be inclined to agree with the interpretation taken by the Licence Committee that the Courts would take the view that these types of embryos are to be covered by legislation. Although this may be the approach which would be taken by the Courts, that is not to say that the average lay person would agree that an embryo created using animal eggs, even though they have had the animal DNA removed, are fully human embryos. This is an area for ongoing ethical debate.
However, if the proposed new legislation comes into force the regulation of hybrid embryos will be without doubt. The Human Fertilisation and Embryology Bill 2008 makes provision for the specific regulation of hybrid embryos, and as such they will clearly be within the remit of the HFEA, and all scientists working in the UK will need a licence to create and conduct research upon such embryos.
Following criticisms of the provisions within the Draft Bill the Government altered the provisions to those now found in the Bill being debated currently. Hybrid embryos are referred to as human admixed embryos in the Bill. Introduced on the 15th January 2008 to amend references to inter-species embryos (as they had previously been referred to) it was felt that the term 'human admixed' embryo was preferable as 'It was felt that the word "human" should be used to indicate that these entities are at the human end of the spectrum of this research...The term "admixed" is preferable as it...is used in the chemical sciences to refer to a substance where two or more components are mixed in to each other...This term...allows for more focused debate on the research issues addressed in the Bill' (6).
The main implication of allowing the creation of and research upon human admixed embryos to be governed by the HFEA is the possibility of perfecting stem cell extraction techniques and pursuing research upon the extracted stem cells without the use of valuable and scarce human eggs. Once scientists have perfected their techniques and undertaken the research necessary to understand the disease which they are researching, they can then use donated human eggs to create the required embryos, extract the stem cells and then use them in clinical trials or therapy, whichever stage the research has brought them too. The numbers of human eggs used in the research process should be dramatically reduced by using animal eggs instead.
The applications by the two research centres in November 2006 pushed the issue of using hybrid embryos for research firmly into the spotlight. The desire to carry out such research has impacted the UK legislation already, in the sense that the HFEA has interpreted the current legislation to include such embryos, and the research has impacted the proposed legislation as hybrid embryos are specifically referred to and will be governed if enacted as the Bill currently stands.
As reported in previous issues of BioNews the use of animal eggs in human embryos is one of the contentious issues upon which MPs will have a free vote. The result of this vote will be very interesting as it is hard to predict which way the majority will go.
The scientific developments of the last 30 years have been rapid and astounding, what is also amazing is that the legislation has kept pace with these developments. When the HFE Act 1990 was undergoing discussion and subsequent enactment, hybrid embryos were not considered. In fact human embryonic stem cell research, which is the reason for creating these hybrid embryos, was also not discussed. The amendment (through the Human Fertilisation and Embryology (Research Purposes) Regulations 2001) and reinterpretation of the HFE 1990 Act to include both human embryonic stem cell research and hybrid embryos shows that the Act has managed to keep pace relatively well with scientific developments which were not even heard of at the time of enactment. Whilst the Act is undoubtedly in need of reform, which is currently ongoing, it is to be hoped that any resulting new legislation is able to deal with future scientific developments in the manner in which the HFE Act has successfully done so.