Human Genome Project/Freeman Dyson Interview (LONG)
- This is an excerpt from the February issue of Wired magazine. It's taken from
an interview conducted by Stewart Brand with Freeman Dyson (a retired
professor of physics, a futurist, and Esther's dad). One of the topics
discussed was the Human Genome Project (described as "a scientific undertaking
by the US Department of Energy and the National Institutes of Health to
identify the chromosomal location and chemical structure of every human
"Q. What are the next tool revolutions we need in science?
A. One is a DNA-sequenced analyzer that sits on your table. There's a lot of
hype about the Human Genome Project. Already we have about 100 identified
genes associated with particular diseases, but it's all far too slow and
expensive. It's ridiculous -- you pay billions for one sequence, and it's not
what the world needs. It's not sustainable. What you really want are
thousands of sequences of all kinds of people with all kinds of diseases, and
animals and plants. The goal is to sequence the whole biosphere. But the
cost has to be reduced by a factor or 1,000 to make it worthwhile. The human
sequence should be US $1 million or less -- done on your desktop, about so
Q. You're gesturing about a foot and a half square -- it looks about the size
of a scanning tunneling microscope.
A. It's the sort of device that will sequence the molecules one at a time so
you don't have to do al this chemistry to multiply them and purify them. You
simply take a single piece of a chromosome and sequence it as an individual
molecule --using physics instead of cemistry.
Q. Explain what you mean by 'using physics instead of chemistry'.
A. It's not a new idea to run a molecule of DNA through some device and
physically chip off one base at a time. The four base types have different
masses, so if you could detach them reliably, one by one, and run them through
a mass spectrograph, it would take, maybe, a few microseconds to separate them
Q. It really is one molecule at a time. You're not talking reactions or
A. The present way of doing it is very ingenious, but it's wet chemistry
--slow and extremely laborious.
Q. If you could read DNA one base pair at a time, could you also manufacture
it the same way using the same tool?
A. We don't know how to do that, but the synthesizers they have now are
pretty good. Obviously, it would be nice if you could do it quicker. The
lack of the analyzers is the bottleneck. No doubt synthesizers will keep on
improving, but when you synthesize DNA, you want to synthesize fairly large
quantities. Therefore, it automatically becomes chemistry.
Q. What do we arrive at when we get that sort of reader?
A. We get the human genome for $1 million. We find out much more precisely
the correlation between different medical conditions and different genes. We
also find out much more precisely the evolutionary relations between humans
and all kinds of creatures, all the way back. This whole business of genetic
analysis is currently based on taking out little bits of DNA. If you had
genomes of everything, it would be far more illuminating.
Q. We could read history straight. We could date things.
A. It would be a tremendous breakthrough for both science and medicine.
The other tool, which is even more important, is a protein structure analyzer.
Most of the really important medical problems are concerned with proteins.
The joke is that there are about 100,000 different proteins in each human cell
-- a minimum of what you want to know. But a few hundred thousand proteins is
probably what we would like to have structures for to design drugs
efficiently. Presently we have done about 5,000 in about 40 years or so. The
first was discovered by Max Perutz.
Q. What was the protein?
A. Hemoglobin. Actually, myoglobin was done about a year sooner. Myoglobin
was done by John Kendrew and hemoglobin by Perutz. They both won a Nobel
Prize. It was a heroic effort. Since then, we've done about 5,000 more.
Many labs are specializing in this area, but it's extremely laborious work.
You have to crystallize the stuff before you can even start. And many of the
important proteins are membrane proteins, which are noncrystallizable. They
have very awkward shapes that are half inside the cell and half outside.
Q. Reading structure must be different than reading base pairs.
A. Much harder. You're required to know the exact geometrical arrangement.
The classical way to do this is by X-ray crystallography, and you can do a
little with MRI (magnetic resonance imaging). Nowadays, most small proteins
are done using MRI. But it doesn't work with the big proteins."
Dyson goes on to discuss "where other tools breakthroughs will
happen"...combining the resolution of the atomic force microscope with the
penetration of MRI...nanotechnology and its realtionship with biotechnology,
and so on.
I thought this might be practical and stimulating enough to be thought-
provoking. Sorry for the length.