First artificial DNA can create new forms of life
25th Jan 2000
Scientists have made the world's first synthetic DNA - the molecules
that form the blueprint for life.
The breakthrough means that the first artificial organisms could be
"born" within two years and raises the prospect of humans redesigning
whole species, including themselves.
The DNA was created at the University of Texas where researchers have
mapped out the exact way it will be configured to create synthetic organism
one (SO1), the microbe destined to be the world's first man-made creature.
"We are synthesising DNA to create the first synthetic organism," said
Professor Glen Evans, director of the university's genome science and
technology centre. "SO1 will have no specific function but once it is
alive we can customise it. We can go back to the computer and change
a gene and create other new life forms by simply pressing a button."
The researchers are planning to create a series of designer bugs, with
super-efficient mechanisms for infecting target tissues such as cancer
tumours - and then killing them. Some would infect the human gut to
produce vitamin C.
Critics, however, have warned that the scientists risk unleashing a
microbe master race with increased powers to infect humans and wildlife.
The researchers' success lies in having found a way to create long chains
of DNA. Such chains are made up of four types of molecule which join
up in twosomes known as "base pairs". The base pairs then link to form
a ladder that twists into the famous DNA double helix.
In nature, one chain of DNA can contain hundreds of thousands of base
pairs. Until now, however, scientists have found it impossible to join
together more than 100.
Evans's team has broken this barrier with a technique that first creates
short chains of DNA and then joins them together in a controllable way.
The scientists are close to achieving chains that contain 100,000 base
pairs - enough to form the basis for simple life forms.
The design for SO1 is based on analyses of the genes of other small
bacteria. Genes are the functional units of DNA, each one being responsible
for creating a protein essential to processes such as respiration. Evans
plans to copy the vital genes from each bacterium, select the best and
join them together. In nature all DNA also contains "junk genes" with
no function but Evans plans to omit these - possibly making SO1 the
most efficient organism that has lived.
The work to create SO1 is complex but the test of success will be simple.
Can SO1 feed and reproduce? If so, then Evans will indeed be celebrating
new life. Opponents, however, will regard such an event very differently.
Tony Juniper, policy and campaigns director of Friends of the Earth,
said the bugs could present a serious threat to human health and the
environment. He said: "Scientists have already unleashed genetically
modified organisms and we are now seeing the damage they can do. Playing
God by creating entirely new life forms could have very serious consequences
which should be publicly and fully debated."
Others are less perturbed. Michael Reiss, a specialist in bioethics
at Cambridge University, said he would become concerned only if such
life became sentient. "In the 19th century people thought there was
some vital essence to life and there was real controversy when the first
organic compounds were made. My own view is that DNA is just an extension
of that process," he said.
Evans believes that man will one day be able to create complex life
forms. For now, however, the first benefit could be simpler - the end
of the vitamin pill. "Humans need but cannot make vitamin C because
we lack one particular enzyme," he said. "If we put that enzyme into
one of our artificial organisms and drink it, the bug will live in our
guts making vitamin C for ever."
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