The recent creation of a "synthetic organism" by Craig Venter and his colleagues his hit the headlines. By all accounts it is a thoroughly impressive piece of work, a tour de force that designed a genome from scratch, literally by writing it the way a piece of computer code is written. The perseverance and ingenuity put into the process deserve ample applause. And it should rightly catapult the emerging field of synthetic biology into the public discourse.
But it's still not a "synthetic cell" in my opinion. The genome was inserted into a cell where it started working exactly as expected. I would not hold my breath before we can design completely synthetic genomes that can do whatever we want, including eating CO2 or producing Lipitor.
To this non-expert, the reason looks simple: everything in molecular biology that we have encountered until now has turned out to be more complex than expected. Notice what's happened to AIDS vaccines, gene therapy and treatments for Alzheimer's disease, all of which would supposedly be simpler than designing a synthetic organism. In each of these cases, what seemed obvious and straightforward has turned out to be a maze of unexpected challenges and unexplained observations. The fact is, designing a genome is one thing, making it produce proteins that will interact with each other in a carefully orchestrated manner, will find binding partners with exquisite specificity and accomplish the extremely complex and often non-intuitive cascades of signal transduction is quite another. A cell is not just the genome, it's really about interactions. And I am willing to bet that we are a long way off before we can generally design all those countless specific interactions which give rise to that entity named a "cell".
Exactly! It would be a synthetic cell if you can synthesise everything in it. Now at best it can be called a "composite" cell if you will. It's the usual genetic engg. carried to greater lengths, definitely remarkable, but synthetic life? not really.
ReplyDeleteWhile the ambitions to 'engineer life' are there, nobody said it would be an easy road from here! Everyone is aware that even the simplest bacterial genomes are complex and beyond our full understanding. No-one expects new fuel-producing bacteria to be announced next week. Yet, the ability to synthesize a genome from scratch is an immense achievement.
ReplyDeleteCompare this to the overhyped presentation of the human genome, which was nearly heralded as bringing an end to all human diseases, and I think the presentation and response of this research have been quite balanced.
It's a great achievement, BUT essentially what they've done is make a new book and insert it into a reader, which read the book and created at new reader from it. The complexity is in the reader (e.g. all the molecules of a cell including membrane, enzymes, riboswitches, substrates, inhibitors, ions etc. etc. in exactly the right proportions and relations to each other). The complexity is the way the parts are put together, not in the parts taken separately, regardless of how complex they are physically. Dissasemble a jet plane into the parts, change one, and see how naturally they come together to produce something that flies.
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