Scientists
a step nearer to creating artificial life
http://www.guardian.co.uk
·
New progress towards synthetic organism · Hope of fuels,
drugs and ways to fight pollution
James Randerson
To the untrained eye, the tiny, misshapen, fatty blobs on
Giovanni Murtas's microscope slide would not look very
impressive. But when the Italian scientist saw their telltale
green fluorescent glint he knew he had achieved something
remarkable - and taken a vital step towards building a living
organism from scratch.
The green glow was proof that his fragile creations were
capable of making their own proteins, a crucial ability of
all living things and vital for carrying out all other
aspects of life.
Though only a first step, the discovery will hasten efforts
by scientists to build the world's first synthetic organism.
It could also prove a significant development in the
multibillion-dollar battle to exploit the technology for
manufacturing commercially valuable chemicals such as drugs
and biofuels or cleaning up pollution.
The achievement is a major advance for the new field of
"synthetic biology". Its proponents hope to construct simple
bespoke organisms with carefully chosen components. But some
campaigners worry about the new technology's unsettling
potential and argue there should be a moratorium on the
research until the ethical and technological implications
have been discussed more widely.
One of the field's leading lights is the controversial
scientist Craig Venter, a beach bum turned scientific
entrepreneur who is better known for sequencing the human
genome and scouring the oceans for unknown genes on his
luxury research yacht. The research institute he founded
hopes to create an artificial "minimal organism". And he
believes there is big money at stake.
In an interview with Newsweek magazine earlier this year, Dr
Venter claimed that a fuel-producing microbe could become the
first billion- or trillion-dollar organism. The institute has
already patented a set of genes for creating such a
stripped-down creature.
Ultimately, synthetic biologists hope to create the most
efficient form of life possible, with the fewest genes needed
to allow the organism to grow, replicate and proliferate. But
researchers have approached the problem from two radically
different directions. Dr Venter's team is starting with one
of the simplest forms of cellular life known to science - the
bacterium Mycoplasma genitalium, which causes urinary tract
infections. By stripping out each of its 482 genes and
observing the effect on the organism they have calculated
that a core of 381 are vital for life.
In contrast to this top-down approach, Dr Murtas, at the
Enrico Fermi research centre at Roma Tre University in Italy,
and Pier Luigi Luisi aim to build a living thing from the
bottom up. "The bottom-up approach has the possibility of
creating living systems from entirely non-living materials,"
said Tom Knight, an expert in synthetic biology at the
Massachusetts Institute of Technology.
"That's the real power of synthetic biology ... If you can
take it apart into little bits and pieces and shuffle things
around and put it back together and it still works, you can
have much more confidence that you really understand what is
going on."
The Italian team's advance is to make simple cells which are
essentially bags made up of a fatty membrane containing just
36 enzymes and purified ribosomes - microscopic components
common to all cells which translate the genetic code into
protein. The primitive cells are capable of manufacturing
protein from one gene.
The team chose a fluorescent green protein found in jellyfish
because it was easy to see, using a microscope, when the
protein is being made. "We are trying to minimise any system
we put in place for the cell," said Dr Murtas. "We can prove
at this point that we can have protein synthesis with a
minimum set of enzymes - 36 at the moment." He hopes the
project will teach him about the earliest stirrings of life
in Earth's primeval slime some 3.5bn years ago.
"It's impressive work," said Prof Knight. "Protein synthesis
is a wonderful place to start, partly because it is so well
understood and ... you can figure out what is going wrong
relatively easily. But there is a lot more involved in making
cells that are alive ... I think the bottom-up people have a
long way to go."
Dr Murtas acknowledges that his bags of enzymes are a long
way from a fully functioning cell, but it is an important
proof of principle - being able to make proteins is key for
the cell to acquire new functions. Giving it the ability to
grow, divide, partition components into daughter cells
correctly and replicate DNA will be a major challenge,
though. The team will report the work in the journal
Biochemical and Biophysical Research Communications.
Dr Murtas is now working on making cells which are capable of
division - crucial if they are to be truly alive. As the
membrane grows, the team hope it will reach a point where the
cell becomes too big and so gives rise to a pair of daughter
cells.
In June, Dr Venter's research team announced that they had
discovered how to carry out a "genome transplant". They
showed they could move the genetic recipe of one species of
Mycoplasma bacterium into another closely related species.
FAIR USE
NOTICE: This site may contain copyrighted material, the use
of which has not been specifically authorized by the
copyright owner. This website distributes this material
without profit to those who have expressed a prior interest
in receiving the included information for research and
educational purposes. We believe this constitutes a fair use
of any such copyrighted material as provided for in 17 U.S.C
§ 107.
NOTE TO AUTHORS: If you are the author or owner of an article
or video that I have made available through THEINFOVAULT.NET
and you do not wish to have your article or video posted on
theinfovault, please contact me and I
will remove the item.