The Kelly brothers, whose genes were compared in NASA’s “Twins Study” after Scott, left, spent two years in space.

Courtesy of NASA

The Kelly brothers, whose genes were compared in NASA’s “Twins Study” after Scott, left, spent two years in space.

March 16, 2018

Despite National Media Claims, 7% of Astronaut’s Genes Did Not Change In Space

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Despite claims by CNN, Time, USA Today, People, HuffPost, LiveScience and Newsweek, astronaut Scott Kelly’s DNA did not actually change by seven percent after two years in space, according to Prof. Chris Mason, professor at Weill Cornell Medicine and lead of the study.

Kelly’s body and genes were monitored closely during his two-year stint in space and compared against those of his identical twin brother, Mark Kelly, in the NASA-backed “Twins Study” led by Prof. Mason, physiology and biophysics.

“It’s the first study of its kind,” Mason, said in a phone interview with the Sun. “It’s very rare to very comprehensively and genetically monitor someone over multiple years.”

Mason believes this may be the most comprehensive genetic portrait of a subject ever constructed.

However, the extensive research of Mason’s team did not find that seven percent of Kelly’s genome changed after he left the Earth’s atmosphere. While his genes remained the same, what changed was his gene expression — the activity of his cells, using that same genetic code, in deciding when and what proteins to manufacture.

“We’re about two percent different from chimps,” Mason said. “He would have been a different species if seven percent of his DNA changed.”

Spaceflight is a strenuous activity, which can impact processes including gene expression even without leaving Earth’s atmosphere, according to Mason.

Change in gene expression has also been seen in activities such as scuba diving and mountain climbing, according to a NASA statement Thursday.

Kelly’s total genomic expression didn’t change by seven percent, either. Though Mason’s team observed genetic change in tens of thousands of genes while Kelly was in space, the majority of them reverted to their original expression after Kelly’s return to Earth.

The figure refers to the percentage of the genes that changed in space that remained altered even six months after Kelly’s return — an “exciting” result that holds many implications in its own right, according to Mason.

The media told a different story this week, however, as various news sources proclaimed that a fourteenth of Kelly’s genetic code had mutated during his time off-planet. LiveScience, as well as a variety of other organizations, proclaimed that the Kelly brothers were “no longer twins.”

Mason described the media firestorm as “mayhem” and “totally insane.”

“It’s been aggravating to watch people take sentences out of context and create a new narrative,” he said, categorizing the coverage as “fake news.”

“It’s people taking two true statements, and, when you put them right next to each other, implying that one is about the other,” Mason said.

Scott Kelly himself contributed to the coverage by tweeting “What? My DNA changed by 7%! Who knew? I just learned about it in this article. This could be good news! I no longer have to call @ShuttleCDRKelly my identical twin brother anymore.” on March 10.

As of Friday afternoon, Mason had not yet spoken personally to Scott Kelly regarding the situation, but was certain that Kelly was only making a joke. Kelly is currently on leave and was not available for comment to the Sun.

“It’s really surprising to see how fast it snowballed,” Mason said. “But also kind of amazing to see how quickly it got corrected.”

LiveScience issued a retraction of their coverage, while sources such as Time and CNN updated their reports.

Mason urged the public to ignore the media fiasco and focus instead on the future implications of the study.

“There’s so much that’s exciting and new, that’s completely novel, that I don’t want people to get distracted by a little bit of sloppy reporting.”

NASA plans to repeat this study 30 more times, according to Mason, for durations of two, six, and 12 months in space. This will allow further study of the “space genes,” which Mason said changed in ways science has never seen.

“We’re really at the dawn of the era of genomics getting into space,” Mason said. “It’s never been more exciting as a geneticist and a space enthusiast.”

Though the media blow-up could have been avoided with simple fact-checking, Mason said, it did bring more attention to the study, which will be published in its entirety later this year.

“We’re always happy to see people interested in spaceflight,” a NASA spokesperson told the Sun on Friday, in response to the controversy.