Made From Scratch
To better understand how life develops, researchers are attempting to create it themselves.
Synthetic biology, so far, has been about manipulating the genetic code of single-celled organisms. But some scientists want to create life. Though most researchers think this feat is a long way off, a few suppose they’re intriguingly close.
The point at which a collection of inanimate molecules becomes alive is fuzzy. There is agreement, however, that the test of life should include the being’s ability to replicate and evolve. Scientists at the Los Alamos National Laboratory in New Mexico have fulfilled one of these requirements, having created a “protocell” from a droplet of fat compounds. In the cell, they have coaxed a primitive set of DNA to produce more fats so the droplet can grow (once there are enough fat molecules, the droplet automatically divides). But they have yet to make the DNA duplicate in sync with the “cell” dividing—another key requirement for it to be considered living.
At Scripps Research Institute in La Jolla, Calif., molecular biologists Tracey Lincoln and Gerald Joyce are tackling the challenge of synthesizing life in a different way, making a self-replicating genetic molecule with two RNA enzymes that work in tandem, one catalyzing the production of the other. The enzymes have even begun to evolve: As each copies the other, they piece together bits of raw genetic material; as time goes on, the RNAs that become most adept at doing so dominate the population.
Meanwhile, molecular geneticist George Church at Harvard is trying to create entire cells. One of the biggest hurdles is making the ribosome, an intricate piece of machinery that builds proteins encoded by the cell’s DNA. Church and his colleagues reported recently that they have cleared that hurdle, creating a ribosome and getting it to produce a protein called luciferase.
Some scientists fear that synthetic organisms could get loose, perhaps causing disease or damaging the environment, while others argue that creating life is immoral. Luckily, it seems there’s time to ponder those issues.