After spending one year in space, astronaut Scott Kelly made an astonishing discovery about his DNA. Scott Kelly, who is the identical twin brother of astronaut Mark Kelly, tweeted that he learned about the altering of his DNA while reading a Newsweek article. In the tweet, Kelly joked about how he no longer needs to refer to his astronaut brother Mark as his “identical twin”.

Astronaut Scott Kelly’s DNA was altered by a year in space, results from NASA’s Twins Study have confirmed. Seven percent of his genes did not return to normal after he landed, researchers found.

Scott Kelly and his twin brother, Mark Kelly—also an astronaut—were the subjects of the study that sought to find out exactly what happens to the body after a year in space.

Scott stayed on the International Space Station from March 2015 to March 2016, while Mark remained on Earth. This was the final mission for Scott, who spent a total of 520 days in space during his career. –Newsweek

The study looks at what happened to Kelly before, during and after he spent one year aboard the International Space Station through an extensive comparison with his identical twin, Mark, who remained on Earth.

NASA has learned that the formerly identical twins are no longer genetically the same.

‘Space genes’

The transformation of 7% of Scott’s DNA suggests longer-term changes in genes related to at least five biological pathways and functions.

The newest preliminary results from this unique study of Scott, now retired from NASA, were released at the 2018 Investigator’s Workshop for NASA’s Human Research Program in January. Last year, NASA published its first round of preliminary results at the 2017 Investigator’s Workshop. Overall, the 2018 findings corroborated those from 2017, with some additions.

To track physical changes caused by time in space, scientists measured Scott’s metabolites (necessary for maintaining life), cytokines (secreted by immune system cells) and proteins (workhorses within each cell) before, during and after his mission. The researchers learned that spaceflight is associated with oxygen-deprivation stress, increased inflammation and dramatic nutrient shifts that affect gene expression.

In particular, Chris Mason of Weill Cornell Medicine reported on the activation of Scott’s “space genes” while confirming the results of his separate NASA study, published last year.

To better understand the genetic dynamics of each twin, Mason and his team focused on chemical changes in RNA and DNA. Whole-genome sequencing revealed that each twin has more than expected unique mutations in his genome — in fact, hundreds.

Although 93% of Scott’s genetic expression returned to normal once he returned to Earth, a subset of several hundred “space genes” remained disrupted. Some of these mutations, found only after spaceflight, are thought to be caused by the stresses of space travel.

As genes turn on and off, change in the function of cells may occur. –KTLA 


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