Computer-generated, edited genome used to make first synthetic life form — bacteria

Researchers at ETH Zurich have demonstrated a new, cheaper and faster way of building genomes than ever before. The team created the first fully computer-generated DNA sequence — “Caulobacter ethensis-2.0” — which doesn’t correspond to a living, existing organism…. yet. But, the genome sequence was constructed into a physical DNA molecule and placed inside an existing organism with a similar genetic sequence. The synthetic C. ethensis-2.0 is based on the genome of a well-researched, harmless species of freshwater bacteria known as Caulobacter crescentus. In nature, the bacterium thrives in spring water, rivers and lakes worldwide but isn’t pathogenic, i.e., it doesn’t infect plants or animals. It is often picked up as a model organism by scientists studying life processes in bacteria. The genome of C. crescentus has roughly 4,000 genes, only 680 of which are crucial to its survival, an earlier study has shown. Bacteria with this minimal genome seemed to be viable and functional when artificially recreated in a laboratory. [caption id=“attachment_6373291” align=“alignnone” width=“1024”] Caulobacter crescentus under a microscope. Image: Indiana University[/caption] A pair of ETH researchers have now taken this minimal genome of C. crescentus to another level — chemically synthesising it from scratch as a single, continuous ring-shaped chromosome. Prior to this study, bringing an artificial genome ‘alive’ was seen as a tour de force. Their interests were two-fold: to make it much easier to make synthetic genomes, and to address the fundamental question of whether synthetic biology can create “living”, functional organisms akin to natural biology. But one of the two researchers that led the project said that it was also intended as a test of our understanding of genetics. “Our method is a litmus test to see whether we biologists have correctly understood genetics, and it allows us to highlight possible gaps in our knowledge,” Beat Christen, one of the lead researchers from ETH Zurich, said in a press release. Only 580 of the 680 artificial genes engineered in the synthetic genome functioned normally, and researchers intend to troubleshoot before giving it another go.

“With the knowledge, we have gained, it will be possible for us to improve our algorithm and develop a fully functional genome version 3.0,” Christen added. Artificial microorganisms have many potential applications, including in biotechnology to produce complex pharmaceutically-active molecules and vitamins and the production of **DNA vaccines** . It can also be universally applied in any microorganisms, and not just Caulobacter. The technology could bring down the cost of creating and sequencing DNA sequences and the likelihood of mutations, simply because the probability of errors becomes lower with shorter sequences. As promising as the results of the study appear, it opens up ethical and moral questions akin to **gene editing technology CRISPR** . Are we ready to create synthetic life forms? Well, the ETH Zurich researchers “stand ready to contribute to that discussion” whenever the rest of us are.