Scientists inch closer to creating artificial living systems

Scientists are one step closer to developing an artificial protocell - a basic ingredient for creating more advanced artificial life.
Protocells are the simplest, most primitive living systems, but creating an artificial protocell is far from simple, and so far no one has managed to do that.
One of the challenges is to create the information strings that can be inherited by cell offspring, including protocells.
Such information strings are like modern DNA or RNA strings, and they are needed to control cell metabolism and provide the cell with instructions about how to divide.
Now researchers from the Center for Fundamental Living Technology (FLINT), Department of Physics, Chemistry and Pharmacy, University of Southern Denmark have discovered information strings with peculiar properties in a virtual computer experiment.

"Finding mechanisms to create information strings are essential for researchers working with artificial life," said head of FLINT, Professor Steen Rasmussen.

"In our computer simulation - our virtual molecular laboratory - information strings began to replicate quickly and efficiently as expected," said Rasmussen.
"However, we were struck to see that the system quickly developed an equal number of short and long information strings and further that a strong pattern selection on the strings had occurred.
"We could see that only very specific information patterns on the strings were to be seen in the surviving strings," said Rasmussen.
"The explanation had to be found in the way the strings interacted with each other," Rasmussen added.

According to Rasmussen, a so-called self-organising autocatalytic network was created in the virtual pot, into which he and his colleagues poured the ingredients for information strings.
An autocatalytic network is a network of molecules, which catalyse each other's production. Each molecule can be formed by at least one chemical reaction in the network, and each reaction can be catalysed by at least one other molecule in the network.
This process will create a network that exhibits a primitive form of metabolism and an information system that replicates itself from generation to generation.
This autocatalytic set quickly evolved into a state where strings of all lengths existed in equal concentrations, which is not what is usually found. Further, the selected strings had strikingly similar patterns, which is also unusual.

"We might have discovered a process similar to the processes that initially sparked the first life. We of course don't know if life actually was created this way - but it could have been one of the steps. Perhaps a similar process created sufficiently high concentrations of longer information strings when the first protocell was created," said Rasmussen.
The research is described in the journal Europhysics Letters.