|
 Genome research pioneer J. Craig Venter called the bacterial cell
his research team designed and constructed the "most simple of all
organisms." While the human genome possesses more than 20,000 genes,
the new organism gets by with only 473.
"This study is definitely trying to understand a minimal basis of
life," said Venter. But the researchers said that even with such a
simple organism, that understanding remained elusive.
They noted that even though their organism has so few genes, they
were still uncertain about the function of nearly a third of them,
even after more than five years of work.
The researchers predicted their work would yield practical
applications in developing new medicines, biochemicals, biofuels and
in agriculture.
"Our long-term vision has been to design and build synthetic
organisms on demand where you can add in specific functions and
predict what the outcome is going to be," said Daniel Gibson, vice
president for DNA technologies at Synthetic Genomics Inc, the
company handling commercial applications from the research.
 "I think it's the start of a new era," Venter added.
Venter helped map the human genome in 2001 and created the first
synthetic cell in 2010 with the same team that conducted the new
research.
That 2010 achievement, creating a bacterial organism with a manmade
genome, demonstrated that genomes can be designed on a computer,
made in a laboratory and transplanted into a cell to form a new,
self-replicating organism.
Having created that synthetic cell, the researchers set out to
engineer a bacterium by removing unessential genes. The goal was to
use the fewest genes necessary for the organism to live and
reproduce.
Venter said initially "every one of our designs failed" because they
took out too many genes, and had to restore some.
ORCHESTRA, NOT PICCOLO PLAYER
Venter said one lesson was that to understand life, it is more
important to look across the entirely of a genome, an organism's
complete genetic blueprint, rather than at individual genes.
"Life is much more like a symphony orchestra than a piccolo player.
And we're applying the same philosophy now to our analysis of the
human genome, where we're finding most human conditions are affected
by variations across the entire genome" rather than a single gene,
Venter said.
[to top of second column] |
The researchers said they created a minimal cell possessing the
smallest genome of any self-replicating organism. They said a cell
with even fewer genes could be possible although it might, for
example, reproduce excruciatingly slowly.
Microbiologist Clyde Hutchison of the J. Craig Venter Institute in
La Jolla California, lead author of the study in the journal
Science, said the goal is to figure out the functions of all the
cell's genes and make a computer model to predict how it would grow
and change in different environments or with additional genes.
"It's important to realize there is no cell that exists where we
know the functions of all the genes," Hutchison said.
The environmental group Friends of the Earth expressed concern about
the research, citing the lack of government regulations specific to
synthetic biology and gene editing technologies.
"Living organisms like bacteria are not machines to be rewired,"
said Dana Perls, an official of the group. "Not even the scientists
know the biological function of 149 of these genes, which raises
safety concerns. If we don't fully understand the science, it is
more difficult to manage biosafety concerns."
The research might shed light on the origins of life on Earth
billions of years ago. "We may be getting hints of some early
fundamental mechanisms that coincide with some of the most primitive
kind of life forms," Venter said.
"I think as we get the ability to explore further in the universe,
my view is wherever we have the same chemical constituents, which is
almost everywhere, life will happen," Venter said. "But that's a
philosophical point until it's proven."
(Reporting by Will Dunham; Editing by David Gregorio)
[© 2016 Thomson Reuters. All rights
reserved.]
Copyright 2016 Reuters. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed.
 |
