Unprecedented: Synthetic creatures have been produced and are alive

Syn57 is a synthetic version of the bacterium Escherichia coli (E. coli). The creation of this bacterium, which can survive with just 57 codons instead of the 64 genetic codes (codons) that living organisms have used for billions of years, is considered a milestone in the history of synthetic biology.

This sequence of 64 nucleotides, found in our DNA and RNA, instructs cells to synthesize amino acids, the building blocks of proteins. However, in this system, some codons are functionally identical.

So, even though living organisms produce only 20 amino acids, multiple codons serve the same function. These unnecessary repeats were eliminated in the development of Syn57.

The researchers completely removed four of the six codons for the amino acid serine, two of the four codons for alanine, and a "stop" codon from the genome. These changes were combined with synonymous but simplified codons, resulting in more than 101,000 genetic changes.

All these processes were first mapped out in 100-kilobyte chunks on a computer. These chunks were then individually transferred to real bacteria and tested. The chunks were then combined in a non-life-threatening manner, creating a fully synthetic genome.

Researcher Wesley Robertson stated that they questioned whether this process might sometimes lead to a dead end. However, the results demonstrated that life could be sustained with a much narrower genetic structure. This simplification also allows for the reassignment of unused codons to other functions.

The team aims to use these remaining codons to develop synthetic polymers and new macrostructures. Furthermore, because Syn57's genetic structure is "unreadable" to natural microorganisms like viruses, this bacterium is expected to be resistant to viral infections. This trait could prevent viral-related production losses in areas such as industrial protein production.

Syn57's "unreadable" genome could also alleviate environmental concerns surrounding genetically modified organisms, as the risk of genetic information leaking into the environment is minimized. "This way, we can prevent information leakage from our synthetic organisms," Robertson said, noting that this technology could also be groundbreaking in biosecurity.