Chat Ed : Welcome Sir John Sulston!
Sam the man : hello
Sir John Sulston : Hello everyone!
IseeATree : Hi Sir!
Sir John Sulston : Great opportunity to discuss this topic, something I think is very important to all of us... and Happy Christmas and New Year!
Giskard : Will the use of genetic engineering be able to stop cells from degrading and so move us towards immortality?
Sir John Sulston : We shall be talking about that in a later lecture, we shall learn more... but I think there will be limits. I also think that we should die and make room for other people!
Ben Wood : Will our gene numbers escalate as we become bigger mammals like other mammals have done in the past. How many genes will humans hold when we are 20 feet tall?
Sir John Sulston chuckles
Sir John Sulston : I don't think our gene number will change... we are not evolving in that way any more. We are evolving now mainly through our culture and our technology rather than our bodies.
dhodgson : Do you think in future it will be possible to prevent disease by gene testing for them and giving them preventative cures?
Sir John Sulston : We'll talk more in the next lecture about this, but yes I think this will be very important, to match medical care to people's genetic character.
Mark : Will less dominant genes become rarer over time?
Sir John Sulston : We can alter our genetic constitution if we wish... again in the next lecture we will talk about the plusses and minuses of doing so.
Woody : There is a potential danger that genetic information could be used to produce genetically targeted weapons, how practical is this?
Sir John Sulston : I think it's not an immediate risk but I think we should look into all possibilities, and this is one reason why I think this information should be open and public so that everyone knows what's going on.
scibabe : Would it be possible to freeze our genes so that they could be submitted into future generations?
Sir John Sulston : You can freeze an embryo of a mammal - this is done in farming already. The question is, like the cloning question that we just discussed in today's lecture, the child that grew from such a preserved egg that includes all the genes, would not be the same as the person it came from, because it would be an identical twin growing in a new age, taking on the concepts and ideas of that age.
Gudrun : why don't people have blue, green or purple hair - could that be done one day?
Sir John Sulston : In theory yes... indeed it would probably quite easy. But personally I would not want to interfere with my genes for such a purpose because the side effects would be uncertain. I'd rather just use dye :)
Claire : Sir John, do identical twins have identical fingerprints on their hands?
Sir John Sulston : No, curiously! Fingerprints are partly environmental in origin, and so identical twins have different fingerprints.
Adrian Stephens : Would a clone taken from an adult's cell live as long as a non-clone?
Sir John Sulston : This is being debated at the moment. Probably ways can or will be found to reset the age of the old cell. At the moment it's uncertain though.
Terry : If Christopher Reeve is cloned to produce bone marrow that could possibly heel Christophers medical condition, what happens to the cloned Christopher after the Original Christopher has been heeled?
Sir John Sulston : This is huge. This is precisely the ethical dilemma of cloning. If you believe that the ball of cells - the very young embyro - is already a person, then you have a problem. If you feel that this is not an issue, then you simply discard the ball of cells once the stem cells (not bone marrow) to cure him have been produced.
Brian : Is it true that the current models for DNA replication would result in so much energy generated that cells should not be able to survive or have theories of replication advanced to fit within current physical laws?
Sir John Sulston : In reality it isn't a problem.. You may be thinking about earlier ideas that required the whole DNA molecule to twist as the strands are unwound. What actually happens is that the strands constantly break and are rejoined to take up the strain, so that the whole DNA does not have to twist, and so there is not an energy problem.
Gemma : i have one attached earlobe and one detatched earlobe. why?
Sir John Sulston : Well that's very interesting! I guess there are also environmental influences on this characteristic.
Steve : Are cloned animals truly identical copies when you consider that the mitochondrial DNA be from the host animal?
Sir John Sulston : Good point. We are thinking only of the vast majority of genes that live in the nucleus. For Ian Wilmut's purposes, this is fine because the new genes carried in the farm animals that he produces are in the nucleus. But you're right, it is an added reason why a clone of a human being would not be exactly the same as the originator of the DNA. But as we said in the lecture, there are lots of other reasons as WELL why that clone would not be identical.
TSam : Briefly, what are your thoughts on the work of the two scientists that are trying to produce the first ever cloned human being?
Sir John Sulston : Ian Wilmut summarised my own thoughts: I sympathise with people who desperately want a child, but I think that the hazards and social consequences of cloning human beings are profound.
Chris : What is your opinion of GM foods, the media make a lot about it, is there really a danger?
Sir John Sulston : There is no inherent problem in GM technology... except that as with all new technologies, we should proceed carefully and with plenty of testing. Personally, I think that it is a good idea to label GM foods so that people have a choice. In this way we can proceed democratically and try them out.
Bern : Could the genetic code be manipulated so that it could never be cloned, similar to what some music companies are doing to their CD's at the moment?
Sir John Sulston laughs
Sir John Sulston : Don't try it with mine!
Sir John Sulston chuckles
Sir John Sulston : Because every DNA code is unique... apart from identical twins... we can easily find out whether a particular person has been cloned and so... unlike the music companies, we always know the source.
Heeran : Doesn't cloning interfere with the correct methylation of the DNA, and how would we be able to get round that, if at all?
Sir John Sulston : Probably the success of cloning depends on resetting the methylation of the DNA as part of the process.
atm : I heard that there had been some worthwhile results of treating spinal cord injuries in rats - is that true?
Sir John Sulston : I'm not expert in this field... but certainly there have been a number of partially successful experiments in treating the nervous system with new cells... another example is the treatment of Parkinson Disease sufferers.
Annabel : If we wanted to find out more about genetics, where would you advise someone to do work experience (17 years old)?
Sir John Sulston ponders
Sir John Sulston : Any University or Institute that does molecular biology and molecular genetics - wherever is more convenient for you - you should simply apply in the usual way.
barry fitzgerald : Why do ID twins have visibly different features (are there some slight genetic variations)?
Sir John Sulston : No. There is essentially no genetic variation. It's almost always due to environmental influences, which begin in the womb. For example, identical twins can have quite different birth weights. So it's not surprising if sometimes their features are a bit different also.
Joe Doherty : You mentioned that humans originated from Africa and we spread across the globe. Why do you think Chinese / Japanese people developed the different shaped eyes.
Sir John Sulston : This is an example of the variation that was picked up on our migrations. We can't say why the eye shape is different, and whether there was any advantage to it, but it certainly so happened that the group travelling east had this different genetic allele or set of alleles.
Jean Egerton : I have heard that there are some people with one blue eye and one brown, how could that be?
Sir John Sulston : Yes, heh, to be honest I don't know! But I have heard the same myself.
Dawn : Who has final say on acceptable uses of genetic technology?
Sir John Sulston : There are a series of advisory bodies... who deal with the use of genetics and clinical embryology (the treatment of human embryos) and they advise the government, who in turn are elected by us. So... the decisions in the end are democratically decided by everyone in the country, and that's the way it should be.
Sue : Can you recommend further reading on the material covered by your lectures
Sir John Sulston : Begin with the booklet that's available, advertised on the website. In there are references and websites for further information.
Mike Derome : What % difference in DNA is needed before a different species arises?
Sir John Sulston : I think you can't put an exact figure on it. It could be large, it could be small, what matters is that the members of the two species can no longer breed together. So some crucial genes could make the difference even though the DNAs were very very similar.
Chat Ed : We're coming to the end of our half hour now, so here's the last question... ending on a philosophical note:
Paul : This isn't a religous question, but, it's sort of unfair to think that each one of us is defined by a long string of letters. Do you believe in a spirit or soul? Something that defines us individually? Aren't we just automatons otherwise?
Sir John Sulston : This is for each of us to decide for ourselves. I think we're not automatons of the DNA code because each of us is an individual learning device that picks up experiences and begins to think. And as we think, we become more and more complex individually, with our own personal memories and ideas. For now, that is enough for me. But in the future, when we understand more about the working of the brain, this question may become more immediate for all of us.
Chat Ed : Thanks Sir John, that was great! And that's all folks!
Annabel : Thank you very much sir john...you have inspired me to study genetics further and i love it!
Gareth Jones : Thanks Sir john for a really good lecture look forward to the next one!
MC : bye bye sir jon
Autumn : Thanks for coming Sir John.
unistudent : Thank you very much
Sir John Sulston : I'm so glad that everyone enjoyed it... I found it tremendously rewarding, the audiences were fantastic, and once again, I'd like to say, Carry on exploring!
ThePhantom : Excellent lectures - very interesting.
Sir John Sulston leaves the room
Chat Ed : There is also a colour booklet to accompany these lectures entitled 'The secrets of life: Genes and genetics from evolution to engineering. As well as the science, the booklet includes discussions of the crucial ethical dilemmas: Should we allow human cloning? Should we allow genes to be patented? Should we allow 'designer babies'? To obtain a copy, please send a postal order or cheque (made payable to Channel 4 Television) for 4.95 (including postage and packing) to:
The Secrets of Life
PO Box 4000
Manchester M60 3LL
Chat Ed : Or telephone 0870 5 44 66 99.
Chat Ed : Great one all! There were loads of excellent questions - sorry we couldn't get them all through in the time we had...
