Tuesday, December 18, 2012
Here is the cover for the November 30 issue of Science (click to enlarge). Eighty curious, colorful shapes that look more or less like units of type from an old-style printing press where the text was assembled letter by letter. In fact, if you look closely, you will find the alphabet and numerical digits.
Or a super-complicated LEGO set.
What is it? I you had asked me to guess, I would have been at a loss.
As it turns out, these are computer-generated schematic representations of 3-D shapes built from a "LEGO" set of short strands of DNA, each strand consisting of 32 nucleotides. These little helix-based "bricks," provided in the right mix, self-assemble into prescribed shapes. Ten thousand of these objects could line up across the period at the end of this sentence. (The grey column represents objects with internal cavities.)
I don't pretend to fully understand how this is done, but I'm dazzled beyond measure by the facility with which researchers can now play with DNA. If you want to call it play. You can also call it nano-engineering. The researchers are exploiting the same elegantly simple double-helix chemistry that over 3.5 billion years filled the Earth with its wonderful abundance of life.
A self-assembling LEGO set? You and I are self-assembled LEGO creations. So is the hummingbird. So is the great blue whale and the great white shark. And the bacterium. …ATTGCGGTACCG… T with A. C with G. Weaving, spinning. Every cell a factory churning out proteins.
The cover of Science is neat. It's more than neat; it's dazzling. But it's a piece of cake compared to what's going on -- inexorably, invisibly, inevitably -- wherever on this blooming, burgeoning, life-blessed planet I cast my gaze.