Astronauts Watched As DNA Repaired Itself In Space, Study Reports

The advent of CRISPR/Cas9, a revolutionary method of genome-editing, has enabled countless new disease treatments, sparked profound ethical questions, and earned a Nobel Prize. Now,  genome-editing using CRISPR has been successfully demonstrated in outer space as part of the Genes in Space program, a collaboration between professional scientists and teenage students, reports a study published on Wednesday in PLOS ONE. 

The experiment was developed by miniPCR bio, a life sciences company based in Massachusetts, along with the aerospace giant Boeing, and was performed on yeast cells by astronauts Christina Koch, Nick Hague, and David Saint-Jacques during their 2019 expedition on the International Space Station.

The full results, reported on Wednesday for the first time, revealed that DNA could be cut with gene-editing tools, then observed as it repaired, in a space-based technique that will help prepare future astronauts for the many rigors of long-duration missions into deep space.

“This is a culmination point of the team effort that we started back in 2014, when Genes in Space was founded by Boeing and miniPCR bio,” said Sebastian Kraves, who co-founded miniPCR bio and Genes in Space and is the senior author of the new paper, in an email. 

“Since then, we have been inviting students (in middle school and high school) to submit audacious experiments to study biology in the extreme environment of space,” he continued. “Every year we have been astounded by the creativity and quality of the proposals that have driven several milestones in space biology.”

This particular project, known as Genes-in-Space-6, was the brainchild of four Minnesota high school students: Aarthi Vijayakumar, Michelle Sung, Rebecca Li, and David Li, who are co-authors of the new study. The students originally proposed the idea of using CRISPR as an experimental platform to study the mechanisms of DNA repair in microgravity in 2018. Kraves and his colleagues enlisted the help of researchers from NASA’s Johnson Space Center and the MIT Whitehead Institute, among others, to bring the idea into reality.

“We're finally at the point of having successfully carried out their vision and being able to share the results of these experiments which feels really amazing,” Kraves said. “It's been quite a ride. Being able to make these advanced genetic techniques available to the entire space biology community, on behalf of a really smart and tenacious group of teenagers—that is a real gift.” 

Scientists have been studying the effects of the outer space environment on DNA for years because this topic is so important for the health of astronauts that might one day travel to interplanetary destinations such as Mars. Here on Earth, the atmosphere mostly protects us from the harmful radiation emitted by the Sun and other cosmic sources, but any crew traveling for months or years in space will be prone to these environmental factors, which could damage their DNA and pose serious health risks.

The Genes-in-Space-6 experiment has provided the first platform for examining how damaged DNA might repair itself in space. Kraves noted that the study “does not yet yield data in sufficient quantity to make definitive conclusions about the nature of DNA repair choices made in space,” but rather “established proof of concept that it is feasible to carry out these types of controlled DNA repair studies in space using modern genetic tools.”

“The elegance of this study is that astronauts could trigger the DNA lesions in a very controlled manner using the CRISPR gene editing system, allowing us to target the DNA damage to a gene that when disrupted and repaired would result in a visible color change in the cells,” he explained.

This color shift allowed the astronauts to report back that the technique was working, but “more studies like this one, now at a larger scale, will be needed to definitively answer whether there are any systematic differences in the way cells repair their DNA in space vs. the way they do it here on Earth,” Kraves said.

In addition to mitigating the harmful effects of space travel on astronauts, future gene-editing experiments in space could help pioneer techniques for manufacturing useful proteins or medicines onboard during a long-duration spaceflight. As the study notes, “the ability to transform and genetically engineer organisms in space represents a significant advance and could enable a plethora of future investigations,” which is why Kraves and his colleagues are eager to find ways to build on the Genes-in-Space-6 experiment in the near future.

“There is also a lot that we don't yet understand about how cells respond to different kinds of DNA lesions when they are exposed to a multitude of different cosmic insults,” Kraves said. “More detailed studies can provide a more nuanced view of how cells respond to different forms of radiation that we will encounter as we travel farther, longer, deeper into space, and inform strategies to mitigate the risks of interplanetary travel.”