S P O T L I G H T D E P A R T M E N T S - The Taft School

E N D N O T E
The complete sequence of the human genome
will be known before any of you graduate
from college. This is a monumental task,
but it will be completed. There are about
100,000 genes in the human genome, so
we are basically talking about an extremely
dynamic puzzle with 100,000 pieces.
To date, biologists have been trying to
understand the mammalian organism by
trying to put this puzzle together even though
we only had a small fraction of the pieces.
Human genes are now being cloned at a
dizzying pace. When the genome is sequenced
we will have them all, as well a read-out of
other information in the DNA that controls
the expression of these genes. In this postgenome
era, which is starting right now, the
complete puzzle will be assembled. This will
happen in your lifetime.
The consequences will be enormous.
Right now human proteins can be synthesized
in bacteria used to treat disease. Patients
with diabetes now receive human
insulin rather than insulin from pigs or
cows and are thus spared allergic reactions
to foreign proteins. Rare proteins like erythropoietin
can be manufactured and used to
treat anemia; this was impossible before the
birth of recombinant DNA technology.
Recombinant DNA technology has
in turn given birth to literally hundreds
and hundreds of biotechnology companies,
and they all think they can make a
fantastic contribution to human welfare.
Much human disease has its basis in genetics.
There can be changes or mutations in
an individual’s DNA. This is the basis of
evolution. It is also the cause of diseases
such as cystic fibrosis or muscular dystrophy
or sickle-cell anemia. The molecular
basis of these diseases is now known, and
people will some day be treated by replacement
of defective genes. Soon we will be
able to understand the genetic basis for
complex behaviors and for diseases that are
manifest as abnormal behaviors, such as
schizophrenia and depression. Rational and
more effective therapies will follow.
Here’s another thing that will happen
to you or your children, but it’s a lot
scarier. You will take a little scraping of
skin cells from your newborn child to the
DNA store for a sequence job. Return a
few days later and you’ll be given a CD
ROM containing the DNA sequence—
your child’s blueprint. With some trepidation
you will put the CD in the DNA
reader and get back a printout from this
21st century crystal ball. For example, it
might say, “Your child will be tall, dark,
and handsome, but not very bright. Personality
will never develop depth, and
temper tantrums will be a life-long problem.
He will likely die of a heart attack in
his late 70s if someone does not shoot him
in a bar room fight before that time.”
If this is not bad enough, you have
this nasty feeling that despite assurances to
We must not
strive for less
than making a
difference.
the contrary, the DNA sequence has also
been submitted to the National Institute
in charge of tracking perverts, and the
profile is now available to future employers,
insurance companies, and the FBI.
Alternatively, mistakes could be made and
the printout could proclaim that you are
the proud father or mother of a German
Shepherd with a great pedigree. There are
some real obvious issues here that are going
to be very difficult to control, but the
answer is not to bury our heads in the sand.
We can now produce clones of virtually
anything. You clone a gene by isolating it
from all other genes and allowing it to replicate—thus
producing an infinite number of
identical copies of the gene. You clone a cell
in the same way. But now we can clone mice
and sheep by starting with a single cell from
an adult animal, and there is no technical
barrier standing in the way of cloning human
beings. Here is a great category for the senior
class poll, assuming it still exists: pick your
classmate “who most wants to be cloned”.
But this is no laughing matter; it is
serious stuff, and it poses very serious questions.
Most are repulsed by the thought of
human cloning for the purpose of producing
identical copies of ourselves; some say that it
would be terrible to have even two genetically
identical human beings. They forget
that nature does occasionally produce identical
human twins. Nevertheless, I am happy
to say that human cloning for this purpose is
not likely on the horizon. There is enormous
power in biological diversity.
But think about this— it will likely be
possible to produce a clone of any given
individual that could be “harvested”, to use
a cold word, very early in embryonic life.
This embryonic tissue could then be used to
isolate multipotent stem cells. These stem
cells could then be grown and replicated in
the laboratory and used for transplantation
to replace neurons lost to Parkinson’s disease
or Alzheimer’s disease, liver cells lost to
hepatitis, bone marrow cells lost to cancer
chemotherapy, and so forth. Now the issue
is not so clear cut. We could each clone
ourselves to produce a bank deposit of our
own stem cells to be used to regenerate our
aging or diseased tissues.
Some will advocate such approaches;
some will be repelled by it. Should research
in these areas go forth? Who properly makes
such decisions? Shall we leave it to the
biologists and physicians? I think not. There
is much to be done by ethicists, theologians,
attorneys, legislators, and a host of others—
particularly a very well-informed and very
well-educated public. In general, the public
is woefully ignorant of science. Don’t ignore
it, no matter what your area of primary
interest. All of science will be impinging on
your life with increasing frequency.
The remarks above are excerpted from
Dr. Gilman’s talk at Morning Meeting in
November (see page 24).
Taft Bulletin 33