The synthetic genome

This is the news of the day: scientists fro the Craig Venter Institute generated the first genome of a viable cells. The research has been published on Science Express and in few hours has been diffused and commented around the world. What is the story of this clamorous paper? Scientists used one yeast strain as a model. Firstly, they in silico designed the genome and placed some sequences of control in order to surely distinguish synthetic genome from the natural one. Previous experiences in sequencing helped researchers to well design the synthetic genome. Indeed, we have to remember that the Craig Venter Institute was one of the first institutions to complete genome sequencing of several organisms. They spitted the synthetic genome into small portions and sequentially assembled them. They started from 1kbp units that were amplified in E. Coli, purified and transformed in yeast. Ten 1kbp formed the first 10kb intermediates. In order to control the intermediates quality, multiplex PCR was carried out, by using specific primers that bound the connecting sequences. They repeated the same process also to produce 100kb intermediates, but they directly amplified the DNA in yeast because E. Coli wasn’t able to do it. The final assembling required additional vector sequences and was performed in yeast spheroplasts. The main issue of this step was the removal of natural genome: synthetic DNA was trapped out from agarose plugs and digested. The synthetic genome was then transplanted into host yeast. In the discussion authors outlined how was important the quality control of each step. Indeed, none mutations had to be introduced into the synthetic genome, especially in gene crucial for cell viability. Indeed, they explained that lost several weeks because of a mutation in DNA gene. The novelty of this paper is the capability to produce a synthetic genome compatible with cell life and propagation. Indeed, the technology to produce short or longer sequences, i.e. plasmid, is quite common and already commercially available. In this case, yeast still is able to duplicate and the genome is pretty more complex than a plasmid. Informatics skills to predict the correctness of the final genome are essential to successfully accomplish this project. Finally, some ethical concerns about the opportunity to manipulate genes at this point and generate life arise from similar studies. Authors self invite the public opinion and other scientists to continue the debate about ethics. Indeed, we must keep in mind that the final goal of science advances is the human life improvement, in terms of quality, health, environment and similar researches may have important advantages for overall world and us.