Since the Sumerians first wanted to drink beer, and it was thousands of years ago, Homo sapiens have developed close relationships with Sacharomyces cerevisae, one-celled fungi, better known as brewer's yeast. Thanks to fermentation, people were able to use this microscopic species for their own purposes. Nowadays yeast cells produce ethanol and insulin, they are put on experiments in laboratories.
This does not mean that S. cerevisiae can no longer be improved – in any case, according to Jeff Boike. Director of the Institute of Genetic Systems at New York University, Boyke, leads an international team of hundreds of people whose task is to synthesize 12.5 million genetic letters that make up the genome of yeast cells.
In practice, this means the gradual replacement of each chromosome of yeast – chemically synthesized DNA. Boyke and his colleagues from almost ten institutions dismantle the yeast genome and allow scientists to mix his genes at his discretion. Ultimately, synthetic yeast – Sc2.0 – will be tuned entirely.
"Over the next 10 years, synthetic biology will produce all kinds of compounds and materials with microorganisms," Boike said. "We hope that our yeast will play a big part in this."
Think of this project as something like the first car of Henry Ford – hand-picked and one of a kind. One day, however, we will be quite ordinary in projecting genomes on computer screens. Instead of developing or even editing the DNA of the body, it would be easier to just print out a fresh copy. Imagine designer algae producing fuel; trouble-free organs; revived extinct species.
"I think it could be more than a cosmic or computer revolution," says George Church, who studies the genome at the Harvard School of Medicine.
Previously, scientists have already synthesized genetic instructions that control viruses and bacteria. But yeast cells are eukaryotic, that is, they store their genomes in the nucleus and bind them in chromosomes, like humans. Their genomes are also much larger.
And this is a problem, because synthesizing DNA is not as cheap as describing. The human genome can now be sequenced for $ 1,000, and the price is constantly falling. But to replace every letter of DNA in yeast, Boike will need 1.25 million dollars. Add the cost of labor and calculations to the total cost of the project.
Together with Church and other Bojke, he directs GP-write, an organization that supports international research, which should reduce the cost of designing, developing and testing genomes a thousand times over the next ten years. "We are faced with all sorts of problems as a species, and biology can greatly help us on this planet," he says. "But only if we cut costs."
A scientist named Ronald Davis from Stanford first suggested the possibility of synthesizing the yeast genome at a 2004 conference. However, at that time, Boyke did not see the point. "Why would anyone need to do this?" – so he thought back then.
But Boike came to the idea that making a yeast genome could be the best way to understand the body. Replacing each part, you can find out which genes are needed, and without which the body can live. Some members of the team call this idea "to build to understand."
"This is a completely different way of understanding how living beings are structured," says Leslie Mitchell, an Honored Worker at the NYU Laboratory and one of the main developers of synthetic yeast. "We learn what gaps in our knowledge exist by applying a bottom-up approach in genetics."
Joel Beyder, an informant from the Johns Hopkins University, develops software that allows scientists to see chromosomes of yeast on the screen and track versions as they go their changes, as if in biological Google Docs. In 2008, in order to make DNA, Boike launched a bachelor's degree course at the university called "Build a Genome" (Build a Genome). Students had to learn basic molecular biology, collecting a continuous tape of 10,000 DNA letters that were to go into a project to create synthetic yeast. A little later, several institutions from China joined the project, followed by English, Australian and Japanese people.
"We distribute chromosomes to individual teams like chapters of books, and they are free to decide what to do with them, but so that it 100% matched our goals, "says Patrick Kai, a synthetic biologist at the University of Manchester, international coordinator of the project with yeast.
Boike and his team took eight years to finally be able to present their first fully artificial x omosomu yeast. Since then the project has accelerated. In March last year, five more synthetic chromosomes of yeast were described in a collection of articles in Science, and Boike stated that all 16 chromosomes are now ready for 80 percent. These efforts made it possible to collect the greatest amount of genetic material ever synthesized and then combined.
It also helped that the yeast genome proved extremely resistant to visions and changes in the team. "Probably the biggest breakthrough is that you can torment the genome as you like, and yeast will just laugh," says Boike.
Boyke and his colleagues did not just replace the natural yeast genome with synthetic ones. "Just making a copy would be stupid," says Church. In the DNA of this organism, they also placed molecular gaps, as if invisible gaps in the steel rings of the wizard. This allowed them to mix the yeast chromosomes "like a pack of cards," as Kai says. This system is now known as SCRaMbLE (synthetic chromosome recombination and modification by LoxP-mediated evolution).
The result is a high-speed evolution carried out by human forces: millions of new strains of yeast with different properties can be tested in the laboratory and used in medicine and industry . Mitchell predicts that Sc2.0 will eventually supplant all other yeasts in scientific laboratories.
The final legacy of Boike's project may be the decision which genome to synthesize as follows. The GP-write group initially assumed that creating a synthetic human genome could become a "grandiose task". But some bioethics questioned and thoroughly criticized this plan. Bojke stresses that the group "will not make a project aimed at creating a man with a synthetic genome." That is, there are no design people.
But if ethical considerations are rejected, the synthesis of the complete human genome, which is 250 times larger than the yeast genome, is inappropriate using modern methods. Also, such efforts are not funded. Boyke's work with yeast was funded by the National Science Foundation and academic institutions, but the grandiose GP-write initiative did not attract much support, except for the initial donation of $ 250,000 from the computer company Autodesk. Compare this to the Human Genome Project, which received more than $ 3 billion in funding.
"This is a revolution we do not want to oversleep," Church says. "If the federal government and all 50 states do not want to do this, we will reap what we sow. We will stay behind. "
Meanwhile, the work continues, the reason behind the ground. Among the covers of magazines and group photos, Boyke keeps a quote on the doors of his office, attributed to the genetics of Theodosius Dobzhansky: "Nothing in biology makes sense, except in the light of evolution." No matter how grandiose the project Sc2.0 does not become – even if it leads to the synthesis of the mouse genome or the creation of pigs for the transplantation of organs to people – it is people who will direct this evolution in the right direction. Sc2.0 can become the second most important achievement, which led to the yeast. After the beer.