> Artificial Life
, Craig Venter
> Around the 4.54th Billion Year Man Creates… DNA
Around the 4.54th Billion Year Man Creates… DNA
Here’s a short roundup of Venter’s amazing work.
J. Craig Venter Institute:
Now, this scientific team headed by Drs. Craig Venter, Hamilton Smith and Clyde Hutchison have achieved the final step in their quest to create the first synthetic bacterial cell. In a publication in Science magazine, Daniel Gibson, Ph.D. and a team of 23 additional researchers outline the steps to synthesize a 1.08 million base pairMycoplasma mycoides genome, constructed from four bottles of chemicals that make up DNA. This synthetic genome has been “booted up” in a cell to create the first cell controlled completely by a synthetic genome.
Craig Venter and Hamilton Smith, the two American biologists who unravelled the first DNA sequence of a living organism (a bacterium) in 1995, have made a bacterium that has an artificial genome—creating a living creature with no ancestor (see article). Pedants may quibble that only the DNA of the new beast was actually manufactured in a laboratory; the researchers had to use the shell of an existing bug to get that DNA to do its stuff. Nevertheless, a Rubicon has been crossed. It is now possible to conceive of a world in which new bacteria (and eventually, new animals and plants) are designed on a computer and then grown to order.
That ability would prove mankind’s mastery over nature in a way more profound than even the detonation of the first atomic bomb. The bomb, however justified in the context of the second world war, was purely destructive. Biology is about nurturing and growth. Synthetic biology, as the technology that this and myriad less eye-catching advances are ushering in has been dubbed, promises much. In the short term it promises better drugs, less thirsty crops (see article), greener fuels and even a rejuvenated chemical industry. In the longer term who knows what marvels could be designed and grown?
Other scientists say 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 leading geneticist at Caltech. Dr. Baltimore described the result as “a technical tour de force” but not breakthrough science, but just a matter of scale.
Craig Venter has taken yet another step towards his goal of creating synthetic life forms. He’s synthesized the genome of a microbe and then implanted that piece of DNA into a DNA-free cell of another species. And that…that thing…can grow and divide. It’s hard to say whether this is “life from scratch,” because the boundary between such a thing and ordinary life (and non-life) is actually blurry. For example, you could say that this is still a nature hybrid, because its DNA is based on the sequence of an existing species of bacteria. If Venter made up a sequence from scratch, maybe we’d have crossed to a new terrain.
[Zimmer posts some good links on this area of research]
The synthetic bacteria have 14 “watermark sequences” attached to their genome – inert stretches of DNA added to distinguish them from their natural counterparts. They behaved and divided in lab dishes like natural bacteria.
M mycoides was chosen as a simple microbe with which to develop and prove the technology. It has no immediate application.
Science: (the journal that published the paper)
We report the design, synthesis, and assembly of the 1.08-Mbp Mycoplasma mycoides JCVI-syn1.0 genome starting from digitized genome sequence information and its transplantation into a Mycoplasmacapricolum recipient cell to create new Mycoplasma mycoides cells that are controlled only by the synthetic chromosome. The only DNA in the cells is the designed synthetic DNA sequence, including “watermark” sequences and other designed gene deletions and polymorphisms, and mutations acquired during the building process. The new cells have expected phenotypic properties and are capable of continuous self-replication.
(image from The Economist)