Sunday, March 2, 2008

What is Life?

On to the next big question, What is Life?
This session was kicked off by Craig Venter, describing, in his deceptively boring voice, how close his team was to creating life. The questions he's investigating are:
  • What is Life?
  • Can we pare it down to its most elemental components?
  • Can we digitize it?
  • Can we regenerate a new life out of the digital model?

They've been trying to find the minimal genome that could represent life by working with the micoplasma genitalium. They've knocked out about 100 of its 500 genes that individually seem irrelevant, but feel that what's left could not be booted up to life.

However, they've worked on building up the single circular chromosome of m.g. (about 500,000 letters long). They've used material from the tens of thousands of labs that can produce genes on demand. They build strings about 50 letters long, with overlaps, then splice them together, then splice together those results, until they build the entire 500,000 long chromosome. The next step is to insert the resultant chromosome into another organism to see if it will boot up. Many species have hosted such extra chromosomes and have gone on to reproduce offspring with the new characteristics.

Venter's vision is to custom produce new species with desired characteristics. He says they're about 18 months away from creating an organism that could take CO2 directly from a feedstock and creating biofuel from it, that could completely replace the petrochemical industry - a modest goal. Or design antibiotics or vaccines directly from components.

He assured the audience that self-destruct genes were built into these organisms as a safety factor. In responding to ethical concerns about 'messing with nature' he claimed he was just 'discovering what was already there' (which hasn't stopped him from patenting these discovers, of course!)

Venter was followed by Paul Rothemund, who went into more detail on the origami chromosomes of last year. By writing strings of genetic letters, like coding a program, he can get DNA to fold in interesting patterns - like the whimsical smiley faces he showed us last year.

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