World-leading scientists have called for a halt on research to create “mirror life” microbes amid concerns that the synthetic organisms would present an “unprecedented risk” to life on Earth.
The international group of Nobel laureates and other experts warn that mirror bacteria, constructed from mirror images of molecules found in nature, could become established in the environment and slip past the immune defences of natural organisms, putting humans, animals and plants at risk of lethal infections.
Although a viable mirror microbe would probably take at least a decade to build, a new risk assessment raised such serious concerns about the organisms that the 38-strong group urged scientists to stop work towards the goal and asked funders to make clear they will no longer support the research.
“The threat we’re talking about is unprecedented,” said Prof Vaughn Cooper, an evolutionary biologist at the University of Pittsburgh. “Mirror bacteria would likely evade many human, animal and plant immune system responses and in each case would cause lethal infections that would spread without check.”
The expert group includes Dr Craig Venter, the US scientist who led the private effort to sequence the human genome in the 1990s, and the Nobel laureates Prof Greg Winter at the University of Cambridge and Prof Jack Szostak at the University of Chicago.
Many molecules for life can exist in two distinct forms, each the mirror image of the other. The DNA of all living organisms is made from “right-handed” nucleotides, while proteins, the building blocks of cells, are made from “left-handed” amino acids. Why nature works this way is unclear: life could have chosen left-handed DNA and right-handed proteins instead.
Scientists have already manufactured large, functional mirror molecules to study them more closely. Some have even taken baby steps towards building mirror microbes, though constructing a whole organism from mirror molecules is beyond today’s know-how.
The work is driven by fascination and potential applications. Mirror molecules could be turned into therapies for chronic and hard-to-treat diseases, while mirror microbes could make bioproduction facilities, which use bugs to churn out chemicals, more resistant to contamination.
The fresh concerns over the technology are revealed in a 299-page report and a commentary in the journal Science. While enthusiastic about research on mirror molecules, the report sees substantial risks in mirror microbes and calls for a global debate on the work.
Beyond causing lethal infections, the researchers doubt the microbes could be safely contained or kept in check by natural competitors and predators. Existing antibiotics are unlikely to be effective, either.
“Unless compelling evidence emerges that mirror life would not pose extraordinary dangers, we believe that mirror bacteria and other mirror organisms, even those with engineered biocontainment measures, should not be created,” the authors write in Science.
“We therefore recommend that research with the goal of creating mirror bacteria not be permitted, and that funders make clear that they will not support such work.”
Dr Kate Adamala, a synthetic biologist at the University of Minnesota and co-author on the report, was working towards a mirror cell but changed tack last year after studying the risks in detail.
“We should not be making mirror life,” she said. “We have time for the conversation. And that’s what we were trying to do with this paper, to start a global conversation.”
Prof Paul Freemont at Imperial College London, who was not involved in the report, called it an “excellent example of responsible research and innovation”.
“Whilst the authors clearly point out the need for an open and transparent debate on the development of mirrored living organisms, there is also a need to identify the promise and positive uses of mirror chemistry in biological systems, albeit in a limited and perhaps future regulated manner,” he said.