A category of synthetic organisms called “mirror life” whose constituent molecules are mirror images of their natural counterparts. may pose unprecedented risks to human life and ecosystemsaccording to a perspective article by top experts, including Nobel laureates. Article published in science on December 12, is along with a long report outlining their concerns.
Mirror life has to do with the ubiquitous phenomenon in the natural world in which one molecule or other object cannot simply be placed on top of another. For example, the left hand cannot be flipped to match the right hand. This handedness is found throughout the natural world.
Groups of molecules of the same type tend to have the same handedness. The nucleotides that make up DNA are almost always right-handed, for example, while proteins are made up of left-handed amino acids.
About supporting science journalism
If you like this article, please consider supporting our award-winning journalism subscribe. By purchasing a subscription, you’re helping to ensure a future of impactful stories about the discoveries and ideas that shape our world.
Handedness, formally known as chirality, is very important in biology because the interactions between biomolecules are based on having the expected shape. For example, if the handedness of a protein is reversed, it will not be able to interact with molecules such as cell receptors. “Think of gloves like gloves,” says Katarzyna Adamala, a synthetic biologist at the University of Minnesota and co-author of the paper and the accompanying technical report, which runs to nearly 300 pages. “My left glove won’t fit my right hand.”
The authors are concerned with mirror bacteria, the simplest form of life to which their concerns apply. The ability to create mirror bacteria doesn’t yet exist and is “at least a decade away,” they write, but progress is being made. Researchers can already synthesize mirror biomolecules such as DNA and proteins. At the same time, progress has been made in creating synthetic cells from mirrorless components. In 2010, researchers at the J. Craig Venter Institute in California (JCVI) installed synthetic DNA in a cell the first cell with a completely synthetic genome.
Creating mirror life would require more progress, but can be achieved with significant investment and effort. “We are not relying on scientific advances that will never happen. I can draw a list of things that need to happen to build a mirror cell,” says Adamala. “It’s not science fiction anymore.” Adamala first worked on creating mirror cells, but now fears that if mirror bacteria are created, the consequences could be irreversible ecological damage and loss of life. The paper’s authors, including experts in immunology, synthetic biology, plant pathology, evolutionary biology and ecology, as well as two Nobel laureates, call on researchers, policymakers, regulators and society at large to start discussing the best way forward. understand and mitigate the risks identified by the authors. Unless the mirror’s life showed evidence that it would no they create extraordinary risks, they advise not to carry out research aimed at creating mirror bacteria.
The initial enthusiasm for creating mirror versions of bacteria began with simpler imaginings. The researchers explored the possibilities of working with mirror versions of proteins and other molecules Proteins and other molecules these are the building blocks of such an organism. An example is drugs that need to be re-administered regularly because biological processes degrade the molecules. Mirror versions of biological molecules would not interact with these molecular mechanisms, so a drug constructed from mirror molecules could have longer-lasting effects. .
Many mechanisms of the immune system are also based on the hands. T cells, which are responsible for recognizing foreign invaders, for example, may fail to associate with something in the wrong hands. Therefore, these therapies can prevent the initiation of immune reactions in patients. “A mirror peptide will not degrade easily, which is why they can be great as therapeutics,” says John Glass, a synthetic biologist at JCVI. “We see no reason to ban that.”
A possible application of the mirror bacteria They can be bioreactors, biological factories that use cells or microorganisms to manufacture various compounds, such as antibiotics and other pharmaceuticals. Bacteriophages (viruses that infect bacteria) can destroy bacteria-based bioreactors, costing a significant amount of time and money, but are unlikely to contaminate the bacteria in the mirror because they would not recognize the molecules. Likewise, natural predators, such as amoebas that consume normal bacteria, would not recognize mirror bacteria as food.
It is these supposed beneficial properties that have raised the concerns of scientists. “All the practical applications that drew us to this field are the reasons we’re scared now,” says Adamala. The bacteria’s ability to evade immune responses can cause deadly infections as they multiply unchecked. Unlike viruses, bacteria do not need to interact with specific molecules to infect an organism, and mirror bacteria can infect a wide range of hosts, including humans, other animals, and plants. And the lack of predators can allow mirror bacteria to spread throughout ecosystems.
Many of the authors initially thought that mirror bacteria wouldn’t survive outside the lab, given the lack of mirror nutrients, Glass says, but the report concludes that there are ways to sustain those nutrients that would feed mirror bacteria. The researchers discuss possible biosecurity measures, such as developing mirror phage viruses that can infect and kill mirror bacteria, but conclude that they will not be a sufficient defense. “None of the (authors) have been able to come up with a countermeasure that would be effective enough to save the biosphere from these organisms,” Glass says.
Not everyone agrees that mirror bacteria pose such great risks. “I would say that the mirror-image bacteria would have a huge competitive disadvantage and would not survive well,” says Andrew Ellington, a molecular biologist at the University of Texas at Austin who develops synthetic organisms. He is not convinced that raising an alarm before a threat, nor the existence of technology that could be used to directly create it, is appropriate. “This is like banning the transistor because you’re worried about cybercrime in 30 years,” says Ellington. There is also concern that governments and regulators may not respond as the authors hope, stifling beneficial research. “I’m not particularly concerned about a largely unknown threat 30 years from now compared to the good that can be done now,” he says.
While the exact risks may be uncertain, what is it is certain that any threat remains at a distance. “The technology isn’t here yet, so the risk scenarios are hard to tell, but this paper can start that discussion,” says Sarah Carter, a California-based science policy biosafety consultant and former JCVI policy analyst for biosafety and who works on policy implications. of emerging biotechnologies. “So I applaud this team for looking to the future and attracting attention.
