In Newly Created Life-Form, a Major Mystery

Emily Singer in Quanta:

ScreenHunter_1805 Mar. 24 21.32Peel away the layers of a house — the plastered walls, the slate roof, the hardwood floors — and you’re left with a frame, the skeletal form that makes up the core of any structure. Can we do the same with life? Can scientists pare down the layers of complexity to reveal the essence of life, the foundation on which biology is built?

That’s what Craig Venter and his collaborators have attempted to do in a new study published today in the journal Science. Venter’s team painstakingly whittled down the genome of Mycoplasma mycoides, a bacterium that lives in cattle, to reveal a bare-bones set of genetic instructions capable of making life. The result is a tiny organism named syn3.0 that contains just 473 genes. (By comparison, E. coli has about 4,000 to 5,000 genes, and humans have roughly 20,000.)

Yet within those 473 genes lies a gaping hole. Scientists have little idea what roughly a third of them do. Rather than illuminating the essential components of life, syn3.0 has revealed how much we have left to learn about the very basics of biology.

“To me, the most interesting thing is what it tells us about what we don’t know,” said Jack Szostak, a biochemist at Harvard University who was not involved in the study. “So many genes of unknown function seem to be essential.”

More here.