From the box office to the research lab, a profound
fascination with an ancient molecule is permeating the minds of
business leaders, scientists, physicians, theologians and
historians _ not to mention the people flocking to see Steven
Spielberg's "Jurassic Park."
This molecule, deoxyribonucleic acid (DNA), has become a
common topic of discussion across dinner tables and over petri
dishes. Fast and furious scientific discovery focused on DNA is
unfolding new knowledge that is transforming our understanding of
all sciences including agriculture, evolution, psychiatry and
other aspects of medicine.
DNA has been called the thread of life, the energy of life,
and the code of codes. Understanding what it is, what it does and
where it will lead researchers is exciting as well as critical if
one wants a clear perspective of the new frontier we are
encountering. Locked in the mysteries of DNA are medical
breakthroughs as well as tremendous business opportunities.
To begin understanding the implications of current research
endeavors, it is helpful to understand the basics of DNA.
What is DNA?
In every human cell _ of which there are billions _ there are
23 pairs of chromosomes. One chromosome contains about
3,000-4,000 genes. Every gene contains chemical building blocks
which produce proteins. This is where the extraordinary story of
These chemical building blocks are complex molecular sequences
of DNA. They are found in the nucleus of every cell except red
blood cells. To demonstrate the size of DNA, if each chromosome
was 1,000 miles long, a gene would be one twentieth of a mile and
DNA would be one twentieth of an inch. If all the DNA in each
cell were unravelled, it would stretch around the planet.
DNA holds all the genetic information necessary to orchestrate
the production of proteins. It is the proteins that are
responsible for every life process of the cell _ from carrying
oxygen to contracting muscles. Hence, DNA is often referred to as
the blueprint of life. The structure and makeup of DNA is a
rather recent discovery and is one of the watershed scientific
breakthroughs of our lifetime.
Just 40 years ago, on April 23, 1953, an issue of Nature
published the work of James D. Watson and Francis H.C. Crick
stating that the structure of DNA is a spiral helix. Watson
referred to it as the "stairway to the stars."
This double helix molecule is made up of linked nucleotide
subunits. These subunits consist of a phosphate molecule and a
sugar which form the parallel sides of the helix, with
"stairsteps" of paired sequences of four nitrogen bases:
adenine, thymine, guanine, and cytosine.
The four bases (A, T, G and C) are the alphabet of our code of
life. The pairing from one strand to the other is tightly
restricted. For example, A always pairs with T, and G always
pairs with C.
Watson and Crick's discovery spurred great excitement in the
scientific world. It uncovered the mode in which DNA replicates:
the two strands simply unravel and a new strand attaches with
complementary coding to create identical pieces of DNA. This
finding meant that the source of heredity was found: genetic
information is carried through to each cell and from generation
to generation via DNA.
What advances have been made with our knowledge of DNA?
Since the discovery of DNA and its functions, scientists have
sought to uncover the fundamental questions about human life
which are hidden in this mysterious molecular package.
The Human Genome Project is an illustration of the
international effort to seek the knowledge that lies within the
human cell. This project, funded by the National Institutes of
Health with $3 billion, began three years ago with the mission of
mapping the entire human genome, our genetic blueprint, by the
year 2005. The result: we will be able to identify the exact gene
along the length of each chromosome. …