Scientists have created the world’s first synthetic life form in a landmark experiment that paves the way for designer organisms that are built rather than evolved.
The controversial feat, which has occupied 20 scientists for more than 10 years at an estimated cost of $40 million, was described by one researcher as “a defining moment in biology”.
Craig Venter, the pioneering US geneticist behind the experiment, described the converted cell as “the first self-replicating species we’ve had on the planet whose parent is a computer.” He said the achievement heralds the dawn of a new era in which new life is made to benefit humanity, starting with bacteria that churn out biofuels, soak up carbon dioxide from the atmosphere and even manufacture vaccines.
However critics, including religious and environmental groups, condemned the work. One organisation warning that artificial organisms could escape into the wild and cause environmental havoc or be turned into biological weapons.
The new organism is based on an existing bacterium that causes mastitis in goats, but at its core is an entirely synthetic genome that was constructed from chemicals in the laboratory. The single-celled organism has four “watermarks” written into its DNA to identify it as synthetic and help trace its descendants back to their creator, should they go astray.
“We were ecstatic when the cells booted up with all the watermarks in place,” Venter told the Guardian. “It’s a living species now, part of our planet’s inventory of life.”
Venter’s team developed a new code based on the four letters of the genetic code, G, T, C and A, that allowed them to draw on the whole alphabet, numbers and punctuation marks to write the watermarks. Anyone who cracks the code is invited to email an address written into the DNA.
The team now plans to use the synthetic organism to work out the minimum number of genes needed for life to exist. From this, new microorganisms could be made by bolting on additional genes to produce useful chemicals, break down pollutants, or produce proteins for use in vaccines.
Most scientists agree Venter has achieved a technical feat in synthesizing the largest piece of DNA so far — a million units in length — and in making it accurate enough to substitute for the cell’s own DNA.
But some regard this approach as unpromising because it will take years to design new organisms, and meanwhile progress toward making biofuels is already being achieved with conventional genetic engineering approaches in which existing organisms are modified a few genes at a time. Some other scientists said that aside from assembling a large piece of DNA, Dr. Venter has not broken new ground.
“To my mind Craig has somewhat overplayed the importance of this,” said David Baltimore, a geneticist at Caltech.
Venter’s aim is to achieve total control over a bacterium’s genome, first by synthesizing its DNA in a laboratory and then by designing a new genome stripped of many natural functions and equipped with new genes that govern production of useful chemicals.
The US President Barack Obama asked the White House bioethics commission on Thursday to complete a study of the issues raised by synthetic biology within six months and report back to him on its findings.
He said the new development raised “genuine concerns,” though he did not specify them further.