Life with a synthetic genome

If you haven’t already seen this plastered all over the news, Craig Venter’s team has created the first replicating cell using a completely synthetic genome.

The video of the press conference while a bit dry, is definitely worth watching

I haven’t read the paper yet, so this is a quick summary based on the conference and on reports elsewhere.

First to clear things up, this is not a completely synthetic life-form. Only the DNA of the life was synthesized outside of a cell and then assembled and inserted into a host cell (of another species.) The DNA was made of known sequences with a few added “watermarks” as Venter says. Even so, this is a remarkable accomplishment and if nothing else demonstrates that there is no special “vital force” in DNA that causes life.

What’s even more exciting about this is the technological breakthroughs the team had to make and the insights into what is necessary for life. For instance the number of genes that were “disposable” in an already minimalistic genome, the ability to grow the synthetic genome in a yeast cell, extracting it from there and then transplanting it into the host cell.

The “watermarks” are an interesting feature too. As I’ve gathered from the video, they’ve added the names of the scientists involved as well as 3 quotations in the genome. These messages are themselves encoded (as a kind of puzzle, I suppose.) Also, to make sure this added code doesn’t form proteins, another layer of encoding is used to insert stop codons. As Venter says, “a code within a code within a code.”

The funny thing though is that this code won’t last long if they continue to grow the bacterium naturally. Since the code by design has to be in non-coding “junk” DNA, it’s not going to be conserved evolutionarily. Point mutations will accumulate over time and since the organism has been designed to have a short life span, the code is bound to be garbled quite soon, maybe even before someone has time to break it. 🙂

I should have another post once I’ve grokked the paper and read some more of the commentary online.