Synthetic Life - Cookin' Up a Cell from Scratch

Science fiction authors have long predicted the day when rogue researchers would create synthetic life. From ancient Greek mythology's Prometheus who created men from clay, to Mary Shelley's Dr. Frankenstein who brought dead flesh back to life in 1818, to modern stories such as Flubber. Humanity has always been in awe of the intricacy of living things, and desired the power to bestow life.

Well, we've arrived. Mostly. In May, 2010, the J. Craig Venter Institute (JCVI) announced that they had successfully assembled the first synthetic life form. What exactly did they mean by that?

The Littlest Microbe

Mycoplasma genitalium is a little bacteria with the big distinction of having the smallest genome of any cellular life form. In nature, M. genitalium is a parasite that inhabits primate mucosal surfaces (such as the lungs and genitals). As far as cells go, it requires the least amount of genetic information to keep it running (the smallest software package, you might say), which makes it an appealing organism to copy if you're a synthetic biologist. After all, you don't want to start out at the Jurassic Park level by building dinosaurs. It's good to start small, and it doesn't get any smaller than M. genitalium.

Synthetic Genome

So, what did the team at JCVI mean, when they said that they built a synthetic cell? They did not design a completely new kind of cell ... they built a copy of M. genitalium. The synthetic part was the genome, but I'll get to that in a sec. Firstly, in nature, enzymes in the cell make copies of all the DNA so that the cell can divide into two new cells. It's possible to take all the DNA from one cell and inject it into another cell, but that isn't a new synthetic genome. That's referred to as "cloning" and is the reason Dolly the sheep made headlines in 1996 and Boba Fett is not as unique as you are.

The JCVI team did something new because, instead of borrowing an already-made-just-add-water genome from a living cell, they chemically synthesized a brand new, shiny genome from scratch. This was no easy feat. Chemical synthesis is only accurate and routine for DNA segments less than 100 bps. For a piece of DNA as long as the M. genitalium genome (582,970 bps) it is necessary to build up from small pieces, little by little. No shortcuts yet. The synthetic biology dream is to create DNA "printers", where a researcher (maybe you) could design a genome on your computer, and print out the whole thing in one step. That'll be the day! Hah, when synthetic pigs fly! (Which, you know, could happen).

Boot Up

Another cool bit of science was the "boot up" step. In essence, it was identical to cloning, in that a genome was injected into an empty cell (that still contained all the proper enzymes and membranes for life to exist ... the hardware platform). However, the empty cell that received the synthetic genome was not from M. genitalium. It was an empty shell of from M. capricolium, a different species entirely. As soon as the artificial genome started directing activities in the new cell, it became an M. genitalium cell. It changed species!

One More Step in a Synthetic Life Tradition

J. Craig Venter Unveiling (Watch the First Minute)

More info on the new "species" they created: Mycoplasma laboratorium