Examination of Witnesses (Questions 260-267)|
5 FEBRUARY 2007
Q260 Dr Spink: Is it human or animal,
in your view?
Professor Blakemore: Could I refer
to the Academy of Medical Sciences Working Party, which will be
chaired by Professor Bobrow, which, among other things, will be
examining exactly that question. A possible rule of thumb is that
if what is created contains a full complement of human genetic
material, a full nuclear DNA complement, then it should be classed
as human, and if it contains less then it is animal.
Q261 Chairman: Professor Bobrow,
what is your view?
Professor Bobrow: I rather resonated
with the evidence of the Bishop previously, that one of the benefits
of this whole affair is that trying to think more deeply about
precisely what is the boundary, with cells in a dish, between
human and not human, is actually something that I would not want
to take a quick flyer at. There is a huge gradation of everything
from a single gene in an otherwise completely mouse cell to the
reciprocal, and somewhere along there we have to draw a line.
The definitions of humanity that I know about all apply to things
that walk upon the earth rather than things that live on the bottom
of the Petrie dish, and I am not sure that there is a very straightforward
answer, although I think there is a structured way of approaching
it and having that discussion.
Professor Blakemore: While I agree
with my distinguished colleague from Cambridge, I would say that
the gradations and complexities in science are true but we do
not want to encourage similar gradations and complexities in legislation.
We have to try to find a simple and clean way through regulating
this area of research, or we might end up with a different bill
and a different regulatory agency and a different set of rules
for every one of the graded forms of human-animal cell type.
Chairman: We take your point.
Q262 Dr Harris: Dr Bobrow, about
just less than 10 years ago, the Donaldson Committee concluded
that the use of eggs from a non-human species to carry human nucleus
was not a realistic or desirable solution to the possible lack
of eggs for research or subsequent treatment, and recommended
that funding bodies, I guess like yours, should make a declaration
that they would not fund or support research using the creation
of such hybrids, and indeed other hybrids. The House of Lords
Stem Cell Research Committee took a different view and said if
replacement of human nucleus in an animal egg provided a way of
creating human embryonic stem cells for research. Some might argue
it was more acceptable to use such an entity for research, etc.
Which do you think was correct of those two views, in around 2000,
and which do you think is correct now?
Professor Bobrow: I think the
world has moved quite a bit in those five years in at least two
ways. Firstly, the extent to which this whole area of research
looks promising has actually improved. There are lots of experiments
which have worked, notwithstanding the difficulties we have discussed.
Secondly, I am not sure that anyone at that time quite appreciated
how difficult it was going to be to get a supply of human eggs
on which to base these experiments. In both those respects I think
that there have been such changes that I would take the view now
that one needs to explore every reasonable opportunity to further
the research and not impose unnecessary restrictions
Q263 Dr Harris: Do you think members
of the Donaldson Committee should announce publicly that they
have changed their view on that?
Professor Bobrow: Why should they
do that? Most of the rest of us do not; we just need to move forward.
Q264 Dr Harris: It may well be that
the Chief Medical Officer has not changed his view?
Professor Bobrow: I do not know
Dr Harris: Is he giving evidence?
Chairman: I am hoping that we will be
able to get evidence from him, because I think it is unfair to
ask the Professor what the views are of the Chief Medical Officer,
six years later.
Q265 Dr Harris: No, I was not asking
about his view. I was saying do you agree that things have moved
on since then; that was the question I was asking. I was not asking
any other question, Chairman, and he did answer the question I
asked him. On the question of chimeras, Professor Blakemore, you
talked about chimera testing, to test the pluripotency of adult
cells, or indeed other cells. Do you recognise that involves the
mixing of human and animal material, and indeed the implantation
of the blastocyst into an animal? Are you concerned that the current
wording of the Government's White Paper would outlaw that, if
it is not changed?
Professor Blakemore: I am concerned,
although I recognise that this is an area of deepest difficulty
and that it would not be totally unreasonable to have a period
of reflection, perhaps with a review after some period of time
to see whether the research should either continue, if it had
been allowed initially, or should be allowed to begin, if it had
been banned initially. You are quite right, in order to demonstrate
pluripotency in chimeras which contain, let us say, human stem
cells, it will be necessary to allow the embryo carrying those
human cells to differentiate to the point at which individual
tissues will be discriminable, to see whether the human cells
are contributing to different tissue types, and that would require
implantation and a longer period of development. I think that
could be handled by restrictions, for instance, on the length
of time over which the implanted embryo could develop, not allowing
it to come to term but to the point of organogenesis. One could
think of a fairly simple algorithm which could be employed to
allow that to continue, but I think that area is the most contentious
and difficult and requires further reflection.
Q266 Dr Harris: I think we found
that in our evidence sessions. Are you worried that the wording
of the Government's proposal in the White Paper might make the
creation of models like the Down mouse unlawful? Indeed, what
would that mean for people who were working with the Down mouse,
if they translated the wording of the White Paper into law, because
that is the mixing of human and animal material in an embryo;
it is a hybrid and then a chimera, is it not?
Professor Blakemore: You are absolutely
right, and that was why I said that I hoped that any change in
the law would not be based on, as it were, a general proscriptive
rule with a few exceptions, but that it would be generally permissive,
and then try to identify the areas of real concern, if there were
going to be any prohibitions. It is absolutely true that there
are already a number of extremely beneficial animal models in
medical research. You have mentioned the Down mouse; I would mention
the different forms of Huntington's disease mouse, in which a
single human gene, an aberrant human gene, has been transferred
to the genome of the mouse to create lines which mimic very, very
completely the symptoms of Huntington's disease. Both of those
developments, the Down mouse and the Huntington's disease mouse,
those advances were made in this country and both have been internationally
enormously beneficial in medical research. It would be terrible
to ban their continued use in this country or to prohibit the
development of similar models in the future.
Q267 Dr Harris: Professor Bobrow,
do you think they really meant that, or do you agree with what
Professor Blakemore said; was it conspiracy or carelessness, in
other words, was it just an error that they used the wording in
the White Paper which would appear to cover that, or is there
really a feeling that the public do not really like this sort
of research, which was the basis they gave or implied in the White
Paper for their position?
Professor Bobrow: It is outside
of my expertise what they were thinking of when they wrote that.
Certainly I would agree with Colin's comments, that there are
hundreds of transgenic mice around, many of them of extreme biological
interest, which have all gone through a chimeric stage in their
creation and which teach us lots of interesting things about the
origins of human disease. Banning that would not seem sensible,
and I have heard no other indication of anyone intending to do
that; but as to what the drafters of the Paper said, I think that
is more your territory than mine.
Chairman: I think that is something which
we will return to. Professor Colin Blakemore, Professor Martin
Bobrow and Mr David Macauley, thank you very much indeed for giving