A
Good Read : The Human Genome
A
first working draft of the sequence of the
human genome has been completed as
announced by the Wellcome Trust and the
Sanger Centre in Cambridge England on June
26th, 2000. The Human Genome Project (HGP)
conceived by the Department of
Energy and the National Institutes of
Health in the U.S. began in
1990. The international project which
plans to identify all the genes of the
human body has completed the initial stage
of the work. The HGP is an international
consortium that includes scientists at
16
institutions from the
U.K., U.S.A., France, Germany, Japan and
China. The five largest centres are
located at the Sanger Centre in Cambridge,
England, Washington University School of
Medicine in St. Louis, Baylor College of
Medicine in Houston, Texas, the Joint
Genome Institute in California and the
Whitehead Institute, Cambridge
Massachusetts. Together, these five
centres have generated about 82% of the
sequence.
The
announcement presented to the world in
Cambridge is a fitting legacy to Drs.
James Watson and Francis Crick of the
University of Cambridge who described the
DNA double helix in 1953. To date 85% of
the human genome has been accurately
deciphered. Further work, still to be
finally checked, means that 97% of the
human genome of 3.1 billion DNA bases
(that's a mass of over 1 trillion Daltons
!) has been read. Detailed work will
continue for at least the next two years
filling in gaps to produce a reference
sequence. The sequence will be made
public.
Despite some progress in
the sequencing of DNA by mass
spectrometry, the HGP project carried out
the massive task through a top-down
approach using more conventional
sequencing methods involving amplification
and gel-based analysis. A private company
Celera Genomics
(a division of PE Corporation) in Maryland
U.S.A. have separately pursued the project
(achieving 85% of the sequence to date)
and have recently mapped the genome of
Drosophila melanogaster (fruit fly). The
company had intended to patent some of its
discoveries and to sell this information
to drug companies. In light of the
announcement, Celera now says it will make
its version of the genome sequence
available at a later date.
The
existence of this genetic map will lay the
foundation for a revolution in medical
diagnosis and treatment. Dr Michael
Dexter, Director of the Wellcome Trust,
which committed £210 million to the
Sanger Center in Britian responsible for
sequencing a third of the genome, said the
completion of the first phase of the work
marked a medical landmark that would stand
alongside or even eclipse other great
scientific discoveries of the past. "This
is the outstanding achievement not only of
our lifetime, but in terms of human
history. Our genes make us what we are as
human beings. It's these genes working
together that maintain a healthy
functioning body. Our genes make us
susceptible or resistant to disease;
tolerant or intolerant of medicines. What
the sequence information will allow us to
do is to identify precisely what genes go
wrong when we develop disease. Our common
humanity is set out in the wonderful
spiral staircase that is our DNA, and at
last we can read its letters."