InsideOutregisterevents for schoolsnewsdiscoverget togethersitemap
 
 discover > dna > big questions
THE SCIENCEBIG QUESTIONSQUIZDISCUSSION FORUMTEACHERS' NOTES
Structure
BIG QUESTIONS
New born babies

In the future, will we be able to choose what our children will be like?

It's a strong possibility. Some scientists are convinced that the developments in DNA technology that are already being used in animals will, in time, be applied to humans. Parents could then pick and choose their children's genes to guarantee they grow up to be unusually healthy, or maybe just better looking and more intelligent than mum or dad. If scientists discover which genes are responsible for these characteristics and others such as sporting ability or musical talent, all will go on the menu. Parents will be able to have their very own 'designer' baby.

It's already possible to use genetic testing on very early embryos to help a sick person. A child may have leukaemia - a serious disease that can be cured by a bone-marrow transplant - but no donor is available. The parents may fertilise several eggs outside the body, test to see which embryo carries the right genes to help its sibling, and then implant only the one that does. This has already happened, more than once. Parents may want to go one step beyond and use the same technique to choose an embryo with desirable characteristics such as hair colour or intelligence. Once the genes responsible for these things are known, it will be scientifically possible. But do you think techniques like this should be allowed?

In animals such as mice, it's been possible for quite some time to inject extra genes into a one-cell embryo. If fact, in many labs it is almost routine. But it's not an easy technique: only a small percentage of the attempts actually succeed, and the inserted gene can mess up other genes by not landing in the right place. To use this technique in humans would be too risky.

Mouse scientists have another more efficient way of re-engineering the embryo. It is a targeted 'cut and paste' approach in which the original gene is replaced by an upgraded one. Others envisage using artificial chromosomes that could be engineered with desirable genes and inserted into the early embryo with few drawbacks.

Eventually the technology will be smoothed out, but even when it is, should we use it? What concerns most scientists is that inserting genes into the early embryo means changing genes in the sperm and eggs which will then be passed on to the next generations. Some people argue that tinkering with the human genome in this way, changing the genes of our children, ought to be forbidden.

These are mind-boggling possibilities but they won't be happening any time soon. We are far from understanding what determines most human characteristics, let alone being able to engineer them into human babies.

www.newscientist.com/hottopics/cloning
New Scientist: cloning and genetic engineering
www.ncbe.reading.ac.uk
National Centre for Biotechnology Education (UK)

 

Will scientists be able to create new life forms?

Will scientists be able to create new life forms?

Two American scientists are already planning to do so. In October 2002, Dr Hamilton Smith, a Nobel prize-winning scientist, and Dr Craig Venter, famous for sequencing the human genome, said they could soon have the ability to create a completely synthetic life form in the lab.

Smith and Venter are proposing to create a very simple microbe. But it won't be exactly from scratch. They plan to strip down the genome of the smallest existing bacterium - Mycoplasma genitalium - synthesise a new set of genes, drop them into the bug, and see if the new instructions bring the bug to life. The scientists acknowledge that trying to create a synthetic genome will be intellectually challenging, but they are convinced they will succeed. The work will be carried out at the Institute of Biological Energy Alternatives in Maryland, US.

Why do it? There are some very good reasons for building artificial bugs. Smith's and Venter's goal is to turn raw materials into hydrogen to solve the world's energy problems. These tiny microbes could also be given the right properties to produce new drugs, new vaccines, even new materials for industry. If they succeed, this will bring extraordinary new possibilities for scientists to alter and enhance the natural world, together with difficult ethical security and philosophical questions about the nature of life.

The risk, of course, is the unforeseen. Some worry that something might escape from the lab could cause havoc out in the real world. Others think the technology might be stolen by terrorists and used against us. These are valid fears. As this project pushes ahead, we should get busy making the rules and setting safeguards in place.

But the ultimate question will be: is it alive? If that bug divides and copies itself, it's hard to deny it's alive.

http://www.tigr.org/
The Institute for Genomic Research
http://www.bioenergyalts.org/about.html
The Institute for Biological Energy Alternatives

Does the human genome contain answers to disease?

Does the human genome have the answers to conditions such as diabetes or Alzheimer's Disease?

One of the most exciting things about sequencing our genome is its medical potential. We all want to live long, healthy lives, and understanding how genes contribute to many common diseases is likely to make this wish come true.

Scientists are looking for small variations in our genome that can make some of us more susceptible to common diseases. They are busy collecting all the variant spellings of our genes in order to investigate whether having a C instead of a G in a certain position, for example, can make one person more likely to get an illness such as Alzheimer's Disease or diabetes.

Once scientists discover which changes make a person more susceptible to these diseases, people could be screened to find out whether they are at risk. This would help because a person can make changes to their lifestyle eating less sugar and taking more exercise, for example, to avoid getting ill, or take preventative medicine.

Doctors will also use genetic screening to discover the best drug for a patient. The fact about drugs is that they work well in some people but not in others (for example, steroids help treat some people's asthma but not everyone's) and some people experience side-effects. How well you respond depends on your genetic predisposition. In the future, a doctor may be able to screen a person's genes to find the best drug treatment. People will no longer be prescribed drugs with the 'one size fits all' approach we have at present, but instead, each individual will receive the treatment that best fits their genetic profile.

And as scientists understand more about the genome, and which proteins a gene makes, drugs will become more powerful and more targeted. If, for example, researchers find that a protein is missing in a certain disease, a drug company can design a compound that mimics the supply; if there is too much protein, they might find ways of switching off the gene or blocking the receptor. With the new knowledge provided by the sequence, we can expect more and better drugs to treat diseases like Alzheimer's Disease and cancer for which, at present, there are few options.

But the human genome will not have all the answers. There are environmental factors, which are obviously important. Take schizophrenia - a mental illness which makes people hear voices and suffer delusions. A person's genetic make-up makes it more likely that they will develop the disease but it's not the whole story. The environment is crucial. Researchers know that things like recreational drugs and suffering a viral illness as a foetus, can all trigger the problems. For most diseases, the impact of the environment still needs to be clarified and this will be a long, difficult job.

www.nature.com Nature Genetics
www.ornl.gov/hgmis/ Human Genome Project Information

Can the human genome predict personality?

Can the human genome predict your personality?

No one doubts that hair and eye colour, or diseases like cystic fibrosis are passed on through our genes. But what about our personality? Are violent, aggressive people born that way? Is being gay or intelligent in our genes? Nobody has the answers, although the human genome is helping scientists ask more detailed questions about what is more important: our genes or our experiences during childhood.

The classical way to study whether nature or nurture shape our personality or behaviour is by studying twins. Since identical twins share all their genes, the differences will be down to the environment. So far, scientists have found that half of our personality traits, such as neurotic behaviour or whether you are an introvert or an extrovert are, hard-wired into our genes.

But behavioural geneticists are still finding it difficult to figure out exactly which genes make you smart or slow, aggressive or laid back. This is probably because it's not just one gene that turns you into any of these things but a bunch of them. Scientists first have to work out what these genes are, and then how they interact to make us the way we are.

Yet of all the many thousands of genes in the human genome, the ones involved in our personality and behaviour are the most controversial. People fear that one day our genetic profile could reveal what sort of person you are, even your tendency to behave in a certain way. Many are anxious that genetic arguments might incite intolerance or excuse criminal acts. But it's worth remembering that even though genes play an important role in behaviour, we are much more than the product of our genes. We will always need to look at the environment to explain our behaviour.

http://genome.wellcome.ac.uk/
The Human Genome Project
http://www.kcl.ac.uk/depsta/law/research/cmle/ Centre of Medical Law and Ethics
http://www.iop.kcl.ac.uk/
The Institute of Psychiatry, King's College, London

stem cell

Can we use stem cells to treat disease?

Stem cells are hailed by many scientists as the therapeutic tool of the future. These cells could fix all sorts of health problems, from curing brain diseases such as Parkinson's Disease to repairing hearts and growing new teeth. A lot of hope is pinned on stem cells.

The power of stem cells lies in their potential to turn into a wide variety of specialised cells. The embryo is full of stem cells, and so is the umbilical cord of a new-born baby. Scientists isolate and study them to work out what turns them into a particular type of cell, be it a nerve cell, a muscle cell or a liver cell.

The aim is to cure different diseases by transplanting the right kind of stem cell. For example, Parkinson's Disease is caused by a lack of certain nerve cells in the brain, while diabetes is due to a lack of specialised pancreatic cells. Clinical trials in patients with Parkinson's Disease have already gone ahead and, although the results are promising, there are still many technical wrinkles that need to be ironed out.

Stem cells could also allow scientists to grow new organs for transplant. This would be a great plus since thousands of people die each year waiting for a donor. For it to be possible, scientists must first understand and control the huge amount of signals that tell stem cells to make specific tissues.

But there are those who object strongly to the use of stem cells in medical research. The ethical dilemma revolves around the source of stem cells. Some people argue that all research on stem cells is unacceptable because they can only be harvested from embryos, which, they claim, are potential human beings and therefore have the same rights as human beings. Once again, as with much of genetic research, there are no easy answers.

www.nuffieldfoundation.org/bioethics
Nuffield Council on Bioethics
www.genomebiology.com
GenomeBiology.com

go to top feedback

 

Is beauty skin deep?