The ongoing quest to build life from scratch / by Karen Frances Eng

A synthetic biologist has created artificial cells that can "talk" to natural cells – are they really alive?

How does one go about building a living cell from non-living components? And how will we know if we've succeeded - or even if we're headed in the right direction? Sheref Mansy, a TED Fellow, has been striving to answer the Mansy Lab  at the University of Trento in Italy. For the past six years, Mansy (TEDxUnTN Talk:  Imitating cellular life ) has been trying to make artificial cells that can interact with natural cells. His team has recently achieved a notable success: their partially artificial cells can "hear" molecules naturally released from bacteria, and they can also synthesize and send molecules back in reply. Mansy explains the science behind the breakthrough and discusses the potential implications.

The first challenge in trying to create a living cell is a doozy, since scientists have not settled on a universally agreed upon definition for life.  "There are two common ways to view life: one is self-replicating, and the other is often referred to as autopoiesis, which essentially means the ability to persist over time," says Mansy. "And the so-called NASA working definition  of life says it is a self-sustained chemical system capable of Darwinian evolution, which sort of combines the two approaches."

Mansy's lab, however, has focused on building artificial cells that display a feature associated with life: communication. "All living things communicate in order to increase their chance of survival," he says. "Communication is a good standard for evaluating 'aliveness,' 'because artificial cells can be subjected to a test that measures this ability."

Could an artificial cell pass the cellular version of the Turing testA Turing test is a way of evaluating the intelligence of a machine by assessing how well it communicates. "In the classical Turing test, you have a communicating machine with a person," says Mansy. If the human thinks they are communicating with another human like a machine - in other words, if the machine is responses are indistinguishable from a human - then the machine passes as intelligent.

All living things can communicate chemically with one another. "If we can construct the artificial cells that can be thought of as natural molecules, then we can see whether they are artificial or not." Mansy says.

Start by building your artificial cells.  What exactly does it take to make one? "We take non-living components and put them together in some things that displays the properties of life," says Mansy. "Using lipids, or fat molecules, we make microscopic containers called vesicles." The synthetic DNA. "

Then, try to get your artificial cells to "speak" with several different kinds of bacteria. Mansy and his team spent a number of years trying to get their party to a natural conversation. After much experimentation, they succeeded with a bacterium called Aliivibrio fischeri . "We built artificial cells that could speak the same chemical language as Aliivibrio fischeri , a language this organism uses to decide when to luminesce," says Mansy. The eureka moment: "When we saw light coming from the cultures containing a mixture of artificial and natural cells, we knew we were getting artificial cells to talk with the bacteria."

This is an excerpt of an article originally published on 8 March 2017. To read the full article, visit the TED Ideas blog >>>