The Twin Astronaut’s DNA Really Did Change After a Year in Space—but Not in the Way You Think

April 7, 2018

The Twin Astronaut’s DNA Really Did Change After a Year in Space—but Not in the Way You Think Interesting account of how #press accounts distort: Low oxygen changes in gene expression morph into actual DNA-level mutations

“That’s not what researchers found. It is, however, what NASA’s own Jan. 31 news release initially implied. In the seventh paragraph of the garbly statement, the agency says that one of the “interesting” findings concerns what some call the “space gene.” The awkward paragraph then rushes from “the” space gene to saying that
“Researchers now know that 93% of Scott’s genes returned to normal after landing. However, the remaining 7% point to possible longer-term changes in genes related to his immune system” and some other processes.

Any reporter in a hurry to publish these fun twin findings from spaaaaace could easily have construed that to mean that some of Scott Kelly’s gene sequences literally changed. Except that the news release had already said a few paragraphs earlier that these changes were in gene expression, not the genes themselves. That means that the twins didn’t differ in their sequences but in how they used them. Space Kelly had changes in how his cells were using genes related to bone turnover, low oxygen, high carbon dioxide, and inflammation. These factors are all what you’d expect to change when you’re living in spaaaaace, where gravity doesn’t stress your bones sufficiently, oxygen isn’t as bountiful as on Earth, and you’re living in a tiny space where everyone’s exhaling carbon dioxide all the time. There are no surprises here.”