Scientists Built an Artificial Cell That Grows And Divides Like a Natural One
a new first for genetic engineering, scientists have developed a
single-celled synthetic organism that grows and divides much like a
normal cell, mimicking aspects of the cell division cycle that underlies
and generates healthy living cellular life.
achievement, demonstrated in an engineered unicellular bacteria-like
life form called JCVI-syn3A, is the result of decades of genomic
sequencing and analysis by scientists, exploring the roles individual
genes play inside living creatures.
"Our goal is to know the function of every gene so we can develop a complete model of how a cell works," says biophysicist James Pelletier from MIT and the National Institute of Standards and Technology (NIST).
That led to a new breakthrough in 2010, with scientists at the J. Craig Venter Institute (JCVI) in Maryland designing the first synthetic bacterial cell,
called JCVI-syn1.0: the first organism on Earth with an entirely
synthetic genome, engineered by stripping the natural DNA out of the
bacterium Mycoplasma mycoides.
Several years later, the team took another step forward, creating a species of bacteria in the lab with a genetic code smaller than any found in nature.
This organism, called JCVI-syn3.0, only possessed 473 genes in total – shorter than any known self-sustaining, living organism in the natural world.
while JCVI-syn3.0's miniaturized genetic toolkit enabled it to
perpetuate itself via cell division, it did so in an unusual way,
producing "striking morphological variation" in the new cells it created, which emerged in a variety of different shapes and sizes.
members of the same research team have figured out a way to prevent
these strange morphologies from occurring, with a newly modified variant
of JCVI-syn3.0, known as JCVI-syn3A.
the addition of 19 genes not present in JCVI-syn3.0, the newfangled
JCVI-syn3A is able to undergo cell division in a more normal-looking,
consistent way, with significantly less morphological variation than
Despite the several years of work behind the achievement, there's still a huge amount of mystery wrapped up in these genes.
example, while JCVI-syn3A features 19 new genes, only 7 genes are
thought to play a role in making its cell division processes run in a
more regular fashion. And of those seven, only two genes – called ftsZ
and sepF – have had their functions identified.
how the other five necessarily contribute to JCVI-syn3A's morphological
consistency remains unknown, but one thing is certain: this tiny genome
now represents the new standard for experimentation that could help us
characterize just what these genes do inside organisms.
thus offers a compelling minimal model for bacterial physiology and
platform for engineering biology broadly," the researchers explain in their paper.
Or, to put it another way, as the leader of NIST's Cellular Engineering Group, Elizabeth Strychalski, says:
"We want to understand the fundamental design rules of life. If this
cell can help us to discover and understand those rules, then we're off
to the races."
The findings are reported in Cell.