A team of researchers from ETH Zurich has reported about the creation of a bacterial genome entirely with the help of a computer algorithm. This report was published in the Proceedings of the National Academy of Sciences. The genome is named as Caulobacter ethensis-2.0. Although it is not yet a living microorganism it exists as a DNA bundle.
This new genome was created from the naturally occurring bacteria, Caulobacter Crescentus. It is usually found in spring waters, rivers, and several lakes. It is inherently harmless and thus used as a model creature in the laboratories. The bacteria’s genome has 4000 genes, but most of them are considered as “junk DNA” and around 680 are considered as essential to support its survival.
Apart from this, the gene set also contains several redundancies as many combinations of the amino acids and proteins which are assembled by the DNA often give the same result. As a result of this scientists created a program to find out the ideal DNA combination. The algorithm was able to fully rewrite the genome as a different DNA sequence which did not resemble the original one at all but was still able to perform the biological functions.
This research work is built on the work of Craig Venter, pioneer of American genetics. He was the first person to chemically synthesize the bacterial genome. This work took almost a decade to finish. The main difference between the work of Venter and the genome created by the algorithm is that the latest one contains a totally new set of genes whereas the former one was an exact copy.
Creating an entire set of bacteria genome totally from the beginning is a very complicated task to achieve. It requires very accurate calculations. The team started with a minimal gene set of the Caulobacter, and it created 236 genome segments from it. After this, the segments were tied together. This sounds like an easy task but it is very difficult to execute. It is very challenging as the DNA molecules can easily get stuck to each other and become twisted and messed up.
The natural world has inbuilt genetic redundancies because of which multiple genes can encode for a single protein. Because of this, the researchers used to rewrite the genome using absolutely unrelated genetic sequences and it still provided the same biological functions.
For testing the genome set, the team created several strains of bacteria using both the natural Caulobacter and the segments of the artificially created genome. When they removed the natural genes, it was found that 580 of the genes were still functional. Hence there is still some room for improvement before a fully functional artificial genome is produced.