Memorandum 12
Submission from the Institute of Biology
SUMMARY
1. We commend this inquiry as a timely response
to a fast-evolving field of scientific and social importance.
We believe that the Government should permit, under licence, the
creation of interspecific (sometimes misleadingly called hybrid
or chimera) embryos in vitro for the purpose of research.
We suggest that the creation and use of such embryos should be
subject to the same legal limits, regulation and strict licensing
that applies to research on human embryos. These conditions would
provide sufficient safeguard against inappropriate or premature
application of techniques and procedures on human material, while
permitting research which has the potential to deliver significant
benefits to human health.
INSTITUTE OF
BIOLOGY
2. The Institute of Biology (IOB) is an
independent and charitable body charged by Royal Charter to further
the study and application of the UK's biology and allied biosciences.
It has 14,000 members and over 50 specialist learned Affiliated
Societies.
FACTUAL INFORMATION
3. The category of interspecific embryos
of particular interest to this inquiry is produced by uniting
eggs from one species (often a cow or rabbit) that have been deprived
of almost all their genes with a cell taken from an individual
of a different species (humans, in the case of this inquiry).
The resulting interspecific embryo corresponds genetically almost
entirely to the species contributing the cell rather than the
egg. That it does not do so precisely is because an additional
very small set of genes exists in mitochondria that are widely
dispersed in every type of cell. Since mitochondria are much more
numerous in eggs than in other types of cell, the interspecific
embryos will initially have the mitochondrial characteristics
of the egg rather than the cell donor species. Over time, in cell
lines derived from such embryos, the egg's mitochondria are gradually
replaced by the (human) cell's mitochondria.
4. This type of interspecific embryo is
of particular interest in offering a possible solution to the
severe shortage of human eggs for research.
5. Another type of embryo, interspecies
chimeras are the product of combination of intact embryonic or
other cells from two different species. Making chimeras by injecting
embryonic stem cells into blastocyst stage embryos is presently
the only way of establishing conclusively whether they are normal,
and are therefore safe to transplant into patients. Since it would
be ethically unacceptable to produce such chimaeras in humans,
critically testing the normality of human embryonic stem cells
may depend on injecting them into blastocysts of other species,
unless other reliable assays can be devised.
RECOMMENDATIONS
6. The Institute of Biology recommends that
research on interspecific embryos in vitro should be allowed,
provided that it is regulated and licensed in the same way as
research on human embryos, and is subject to the same stringent
scrutiny and controls.
7. According to the Human Fertilisation
and Embryology Act (1990), a licence for research cannot authorise
any activity unless it appears to the regulatory authority to
be necessary or desirable for a purpose specified in the relevant
regulations of the Act. Moreover, granting of such a licence requires
that the HFEA is satisfied that any proposed use of embryos is
necessary for the purposes of the research. These conditions would
provide sufficient safeguard against inappropriate or premature
use of such novel techniques and procedures on human material
to make it unnecessary to prohibit them through legislation.
8. It is important that research is regulated
and carried out in a manner that earns public confidence and support.
We recognise that there are legitimate ethical concerns about
this area of research, and believe that policy makers should seek
and consider diverse views when developing legislation in this
area. We therefore welcome the forthcoming consultation announced
recently by the Human Fertilisation and Embryology Authority.
9. No general agreement has been reached
on what to call this type of embryo, but it is often referred
to incorrectly and misleadingly as a "hybrid". Terminology
is important. We recommend that a new name is coined for this
type of embryo, which is neither a hybrid (where the egg of one
species is fertilised by the sperm of another, eg mules) nor a
chimera (which combines whole cells from two different species).
Both the terms, hybrid and chimera, are emotive and inaccurate.
10. The committee should note that it will
be necessary to consider how to test whether human embryonic stem
cells are normal before they could be used for human therapy in
the future. At present, chimeras are likely to be the best test
(see paragraph 5).
11. Public support for this type of research
requires scientists to act ethically and to be willing to understand
and address people's concerns and explain the reasons, benefits
and alternatives to this research. The Institute of Biology requires
all members to abide by a code of conduct, and we provide guidance
on ethical codes of practice. As part of continuing professional
development for chartered biologists, we also offer communications
training.
12. Given the fast moving nature of this
area of research, the legislation and regulation should continue
to be reviewed as necessary to take account of the new issues
and opportunities that will arise.
CONTEXT
What sort of research is being proposed?
13. Proposed research includes creating
disease-specific cell lines from a number of individuals with
different neurological diseases that have a known genetic basis,
including Alzheimer's, Parkinson's and motor neurone disease (ie
the patients will have one of several known genetic mutations
that cause a given disease). Cell lines with these mutations can
then be used both for basic research into the causes of these
diseases, to identify and test possible drugs to treat these diseases,
and might lead to possible genetic therapies.
14. For example, embryos may be formed by
removing the nucleus from a cow egg, and fusing the emptied egg
with an intact human cell from an individual with a given genetic
defect which causes a particular neurological disease. The resulting
embryo would only be used as a source of cells for research, and
would not be grown for longer than the 14 day legal limit. The
cells will contain a human nucleus, and human and cow mitochondria.
As the cells divide, the cow mitochondria decrease in number since
the nuclear genes required for forming cow mitochondria are lost
in the enucleation step. This method has been shown to work using
both cows and rabbits as a source of eggs.
Is this research necessary?
15. Because the procedure for creating this
sort of interspecific cell line is currently very new and inefficient,
it may require hundreds or even thousands of eggs to create each
new cell line. Experience may improve procedures and efficiency.
16. Human eggs for research will always
be in short supply and are often of poor quality. Good quality
animal eggs are in plentiful supply, for example from abattoirs
(where they would otherwise be discarded). The use of animal eggs
will avoid the need to carry out potentially harmful and invasive
procedures on human donors.
17. At the moment, the alternative methods
for studying neurological diseases do not show the full range
of human symptoms and may not offer hope of developing new treatments
for these debilitating diseases. The proposed research using cell
lines from human-animal interspecific embryos offers new tools
for both basic research and drug screening. While not offering
the prospect of effective treatments in the short term (nor any
guarantee of therapies or cures), they should reduce the need
for research on live animals as models for certain diseases, and
will accelerate the pace of research since the cell lines will
be deposited in the UK stem cell bank (as required by the HFEA
licence procedure) and will therefore be freely available to researchers
in universities and companies around the world.
18. It is important not to create false
hopes that this research will produce cures for debilitating diseases.
Cures are not guaranteed from any type of research, but the proposed
research offers a good prospect of accelerating scientific progress
in understanding these diseases and testing possible new therapies
which could, in the future, improve the quality of life of people
with different ailments.
19. So far, only a very limited number of
investigations of the growth of embryos obtained by combining
eggs of the cow or rabbit with animal or human cells have been
undertaken. Questions remain about whether cell lines from these
embryos really offer an appropriate alternative to those obtained
either from "spare" human embryos or by combining human
cells and eggs. Given that research on human-animal interspecific
embryos has progressed significantly further than less medically
relevant research on corresponding combinations between different
animals, it seems unwarranted on strictly scientific grounds to
prohibit it now.
January 2007
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