Last week, a group of 150 invited experts gathered at Harvard. Behind closed doors, they discussed the prospects for designing and building an entire human genome from scratch, using only a computer, a DNA synthesizer and raw materials. An artificial genome will then be introduced into a living human cell to replace its natural DNA. The hope is that the cell will "reboot", change its biological processes to work based on the instructions provided by the artificial DNA.
In other words, we may soon see the first "artificial human cell."
But the goal is not simply to create Human 2.0. Through this project, HGP-Write: Testing Large Synthetic Genomes in Cells, scientists hope to develop innovative and powerful tools that will propel synthetic biology towards exponential industrial growth. If successful, we will not only acquire biological tools for designing humans as a species: we will be able to remake the living world.
Creation of life
Synthetic biology is essentially a marriage between the principles of engineering and biotechnology. Whereas DNA sequencing is all about reading DNA, genetic engineering is about editing DNA, and synthetic biology is about programming new DNA, regardless of its original source, in order to create new life forms.
Synthetic biologists see DNA and genes as standard biological building blocks that can be used as they please to create and modify living cells.
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There is the concept of a designer in this area, says Dr. Jay Keesling, a synthetic engineering pioneer at the University of California, Berkeley. “When your hard drive dies, you can go to the nearest computer store, buy a new one, replace the old one,” he says. "Why don't we use biological parts in the same way?"
To accelerate progress in this area, Kisling and his colleagues are putting together a database of standardized pieces of DNA - called BioBricks. It can be used as puzzle pieces to gather genetic material never seen before in nature.
For Kisling and others in the field, synthetic biology is like developing a new programming language. Cells are hardware, hardware, while DNA is software that makes them work. With enough knowledge about how genes work, synthetic biologists hope to be able to write genetic programs from scratch, create new organisms, change nature, and even direct human evolution in a new direction.
Similar to genetic engineering, synthetic biology gives scientists the opportunity to experiment with natural DNA. Difference in Scale: Gene editing is a cut / paste process that adds new genes or changes letters in existing genes. Sometimes it doesn't change much.
Synthetic biology, on the other hand, creates genes from scratch. This gives scientists more room to modify known genes or even create their own. The possibilities are almost endless.
Biomedicals, biofuels, bio-crop
The explosion of synthetic biology over the past ten years has already produced results that have enthralled scientists and corporations alike. Back in 2003, Keesling published one of the very first studies to prove and demonstrate the power of this approach. It focused on a chemical called artemisinin, a powerful antimalarial drug extracted from sweet wormwood (wormwood).
Despite numerous attempts to cultivate this plant, its yield remains extremely low.
Kisling realized that synthetic biology offered a way to bypass the harvesting process altogether. By introducing the necessary genes into bacterial cells, he reasoned, you could turn these cells into machines for the production of artemisinin and provide at their expense a new abundant source of the drug.
This was very difficult to do. Scientists needed to build a completely new metabolic pathway in the cell, allowing it to process chemicals that it didn't know before. Through trial and error, scientists glued together dozens of genes from multiple organisms into one DNA package. By inserting this packet into E. coli - the bacterium E. coli is commonly used in the laboratory to produce chemicals - they created a new pathway for the bacteria to secrete artemisinin.
By tightening the necessary nuts a little more, Kisling and his team managed to increase production a million times and reduce the price of the drug tenfold.
Artemisinin was only the first step in a huge program. This drug is a hydrocarbon that belongs to a family of molecules often used to make biofuels. Why not apply the same process to biofuel production? By replacing the genes that bacteria used to make artemisinin with genes for producing biofuel hydrocarbons, scientists have already made many microbes that convert sugar into fuel.
Agriculture is another industry that can benefit enormously from synthetic biology. In theory, we could take the genes responsible for nitrogen fixation in bacteria, put them into our culture's cells, and completely reverse their natural growth process. With the right combination of genes, we could grow a crop with a full spectrum of nutrients that requires less water, land, energy and fertilizer.
Synthetic biology could be applied to the production of completely new foods, such as fragrances through the fermentation of modified yeast or vegan cheeses and other dairy products created without the help of animals.
“We need to reduce carbon and pollutant emissions, use less land and water, control pests and improve soil fertility,” said Dr. Pamela Ronald, a professor at the University of California, Davis. Synthetic biology can provide us with the tools we need.
Recreating life
Practice aside! One of the ultimate goals of synthetic biology is to create a synthetic organism made exclusively from specially designed DNA.
The main obstacle now is technology. DNA synthesis is currently very expensive, slow and prone to errors. Most of the existing methods make it possible to make a DNA strand 200 letters long; normal genes are ten times longer. The human genome contains about 20,000 genes that produce proteins. But the cost of DNA synthesis has been falling rapidly over the past decade.
According to Dr. Drew Andy, a geneticist at Stanford University, the cost of sequencing a single letter has dropped from $ 4 in 2003 to 3 cents today. The estimated cost of printing all 3 billion letters of the human genome today is $ 90 million, but is expected to drop to $ 100,000 over 20 years if the trend remains the same.
In the 90s, Craig Venter, known for his leading role in sequencing the human genome, began looking for the minimum set of genes needed to create life. Together with colleagues at the Institute for Genomic Research, Venter was stripping genes from the bacterium Mycoplasma genitalium to identify life-critical ones.
In 2008, Venter pieced together these “critical genes” and assembled a new “minimal” genome from a broth of chemicals using DNA synthesis.
A few years later, Venter transplanted an artificial genome into a second bacterium. The genes took root and "restarted" the cell, allowing it to grow and reproduce itself - it was the first organism with a completely artificial genome.
From bacteria to humans
If the new venture gets funding, it will replicate Venter's experiments using our own genome. Given that the human genome is about 5,000 times larger than Venter's bacteria, it’s difficult to say how much more difficult this synthesis could be.
Even if all else fails, the industry will gain valuable experience. According to Dr. George Church, lead geneticist at the Harvard School of Medicine, this project may open up technological advances that will improve our own ability to synthesize long strands of DNA. Church even emphasizes that the main goal of the project is technology development.
However, the meeting of scientists caused a lot of skepticism. Be that as it may, this project could one day lead to the creation of "designer babies" or even humans. The parents of such people can be computers. It's easy to imagine such a future, but it's scary: How safe is it to directly manipulate or create life? Who will own this technology? What to do with a life that has turned out to be unsuccessful? Would all this not create discrimination and inequality?
ILYA KHEL