Wednesday, May 26, 2010

Creating life from scratch... Or not.

There’s quite a bit of hullabaloo (I can’t believe I just used that word) surrounding the recent creation of the first “man-made” synthetic cell. Genomics, the study of DNA sequences of entire organisms, has come a long way in a very short time: after all, Watson and Crick discovered the structure of DNA less than 60 years ago, and already we’re toying with the thing like it’s silly putty.

DNA can be thought of as the recipe book to make an organism. In your DNA, there is all the information necessary to make every single part of your body. Strangely enough, DNA is only made out of four units: A, C, T and G (remember the movie “Gattaca”? That’s a play on a DNA sequence). The sequence of these units determines your genes (small chunks of DNA), your chromosomes (larger chunks of DNA comprised of many genes), and your genome (the sum of all your DNA). To create the synthetic cell, the researchers started with the genome of one bacteria (let’s call it “donor”). They mapped out the genome of the donor into a computer file, and then edited the code, adding a few specific chunks here and there. These added chunks (the “watermarks”) would later serve as markers to confirm that the resulting organism only hosts the synthetic code. Once the researchers had a DNA sequence they were happy with, they fed the code into a machine that spurts out the As, Cs, Ts and Gs in the correct order and generates small pieces of synthetic DNA. The researchers then used elaborate techniques to stitch together the small pieces into a complete genome. Finally, the researchers transplanted this synthetic genome into a different bacteria (the “recipient”) previously emptied of its own genome. Shazam! Synthetic “life”.

At this point, I don’t think we can call this breakthrough “artificial life”. Life was not created from scratch. What we have here is a functioning cell (and that includes the ability to replicate) with a synthetic genome. This synthetic genome, even though it was created from a computer, only includes genes found in nature (and the watermarks, but they don’t code for anything). And while it’s fun to imagine that we’re only days away from reviving the woolly mammoth, it’s important to keep in mind that this synthetic cell has a very tiny genome. What’s more, the genome of the synthetic cell had some mistakes in it: it wasn’t exactly as the researchers had intended.

Still, I think there is cause for concern, both in terms of ethics and biodiversity. If we had already cracked open Pandora’s box with transgenic animals and plants, this represents a rip-the-lid-off-and-break-the-hinges advance. Especially considering that current legislation allows the patenting of such organisms (a subject for a later post, perhaps). However, with all the bad comes some hope: like stem cells and gene therapy, this technique may represent a new hope to cure diseases.

What’s your take on this new breakthrough? A step closer to mastering life and curing diseases, or a scary slide down a slippery slope?

Reference: Creation of a bacterial cell controlled by a chemically synthesized genome. (2010) Gibson DG et al. Science, May 20 [Epub ahead of print]

6 Responses to “Creating life from scratch... Or not.”

Fawn said...

Exciting AND scary! And may I just add that the pic makes me shudder for some inexplicable reason?

How did the errors come about? It that a result of the, um, "natural" way that "life" does unexpected things? (So strange to require "quotes" here...) Or did they make mistakes in their design? Or was it one of their elaborate techniques that messed things up along the way?

Probably, this is the thing what I was looking for. Thank you, for making scientific description easy, I am now looking for about their machine used to make a synthetic strands of genome made from data in computer. Can you give me any link or description about that?

Dr. Julie said...

@ Fawn: Don't shudder, you are covered in bugs that look just like those. :)

As for the mistakes, they weren't in the original design, they occurred and accumulated during the process. My post doesn't really convey how complicated it was to stitch all the small parts of DNA together, but it required many steps, and, well, nothing's perfect. :)

@ Arafat: The original article (see the reference at the bottom of my post) gives details on the equipment they used.

Nina Di Pietro said...

Hey Julie! Love your blog! When I heard about the synthetic cell I was both excited and scared at the same time. I guess it really is just a matter of time before all sorts of things emerge out of petri dishes... not quite sure what to make of it yet.

formerly fun said...

I came over from the Ask review, am enjoying your site. Thought you might also enjoy this blog:

Dr. Julie said...

@ Nina: Thanks for dropping by! I see what you mean, it was only a question of time...

@ formerly fun: Why no longer fun? Welcome and thanks for the link!

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