UPDATE: This story is incorrect. The corrected version is here.
LiveScience:
Scott and Mark Kelly are identical twin brothers — at least, they were until Scott spent a year living in space.
When Scott Kelly returned to Earth after a 340-day voyage aboard the International Space Station (ISS) two years ago, he was 2 inches taller than he’d been when he left. His body mass had decreased, his gut bacteria were completely different, and — according to preliminary findings from NASA researchers — his genetic code had changed significantly.
While most of these genetic changes reverted to normal following Scott Kelly’s return to Earth, about 7 percent of the astronaut’s genetic code remained altered — and it may stay that way permanently.
This is all kinds of mind-blowing and may have real consequences as we go forward into space. Thaks to my friend Mike Rose for the link.
Incredible.
That’s weird. Nothing in this article supports the conclusion in the headline.
Scott and Mark still both have the same DNA sequences. It’s just that the expression of certain genes, present in both of them, was triggered by Scott’s time in space.
I was expecting to read about mutations in Scott’s DNA because of being bombarded with cosmic rays during his time in space. THAT would change his DNA sequence.
holy cow!
Nothing (much) to see here then. Thanks for clarifying.
Since I’ve not had the chance to read the article, did you gather what triggered them exactly? No gravity? Radiation?
It appears that oxygen deprivation stress, increased inflammation, and dramatic nutrient shifts experienced in space affect gene expression — and to a limited extent, DNA sequence.
Although not mentioned in the above article, part Scott’s DNA did change. His telomeres were lengthened but within a couple of days returned to their normal size once he returned to earth. Telomeres do not code for proteins but are nucleotide sequences at the ends of chromosomes that are thought to protect their integrity and thus protect the genetic sequence. Short telomeres are associated with cancer.
Maybe the harsh conditions of space induce the lengthening of telomeres. Exposure to cosmic rays increases the risk of mutations and cancer. Maybe lengthening of telomeres is another way life adapts to space, though stress usually shortens telomeres. Life is complicated and amazing.
Better to read the NASA article: https://www.nasa.gov/feature/nasa-twins-study-confirms-preliminary-findings
The linked LiveScience article is misleading and the headline is idiotic. As others have noted, the Kellys do not have “different DNA”. The 7% refers to changes in gene expression. The only observed change to DNA was the Scott Kellys telomeres were longer in space – a very temporary change.