Synthetic cells were able to evolve

Nature: synthetic cells with the smallest possible set of DNA were able to evolve

Synthetic cells, possessing the smallest possible set of DNA, have shown their ability to evolve, like normal cells. The discovery was made by scientists at the University of Indiana, writes the journal Nature.

A synthetic organism, a modified bacterium Mycoplasma mycoides, was used in the experiment. It has only those genes that are critical to maintaining the life of the cell. The minimum genome contains 493 genes, which is the smallest number among all known cellular organisms. The wild type of mycoplasma has 901 genes, and in multicellular animals and plants there are more than 20 thousand of them.

It is assumed that any mutation in such a simple organism is likely to be lethal, since it affects critical genes. Thus, the evolution of the bacterium Mycoplasma mycoides was thought to be very limited, since it practically lacks genes that can be affected by natural selection.

However, the researchers found that an exceptionally high mutation rate occurred in the synthetic cell. During the experiment, bacteria cells were allowed to multiply freely for three hundred days, which is equivalent to changing 2000 generations of bacterial cells. Through this interval, scientists compared the survival of synthetic Mycoplasma mycoides and wild-type Mycoplasma mycoides by placing them in one tube.

Initially, the synthetic bacterium was 50% less fit than the wild-type strain and could not compete with it in vitro for limited resources. However, the strain that arose as a result of 300 days of evolution restored its fitness, taken away as a result of genome minimization, and even surpassed the wild strain by 39%.