In late January, NASA published a press release on the project “Twins”, during which experts examined the impact of space on the human body. To do this, they compared the analyzes of the twin brothers Mark Kelly, who was on Earth, and Scott Kelly, who spent a year on the ISS.
Six months after the publication, Russian and foreign media published news that the genes of astronaut Scott Kelly had changed after a year of staying on the ISS. Journalists drew attention to the fact that “it’s forever” and wrote that Kelly “returned quite a different person.” Editors of some publications even took seriously Kelly’s joke from Twitter that they can no longer be called twins.
It turns out that Scott and Mark are no longer twins at all. After all, the genetic difference of 7 percent is quite impressive. It is much more than those 2 percent, thanks to which we differ, for example, from chimpanzees.
It turned out that only 93% of the Scott Kelly genes returned to their normal state after landing on Earth, while the remaining 7% of the genes – changed forever.
NASA physicians have established that life in space dramatically changes human DNA. […] It turned out that after Scott’s one-year assignment to the ISS, he ceased to be the complete twin of his brother.
Астронавт Скотт Келли больше не является полным близнецом своего брата Марка Келли – 7% его генов не вернулись к прежнему состоянию после возвращения на Землю два года назад.
— 🗳❌🐷 (@UnicornPigF) March 15, 2018
Astronaut Scott Kelly is no longer the complete twin of his brother Mark Kelly – 7% of his genes did not return to his former condition after returning to Earth two years ago.
Due to the impact of space, two astronaut brothers ceased to be twins.
The work of the genes of one of them changed by about seven percent.
When scientists analyzed the genetic code of Scott Kelly, they came to a sensational conclusion – he returned a completely different person.
The results are as follows: after spending a year in orbit, Scott Kelly returned home literally another person. 93 percent of Scott Kelly’s genes returned to their normal state after he returned to Earth, while 7 percent did not.
The genetic code of Scott Kelly, commander of the International Space Station (ISS) crew, who spent 340 days in space, has radically changed. Scientists have proved that he is no longer the complete twin of his brother Mark Kelly.
Information from the media quickly picked up in social networks. Many users also decided that 7% of the astronaut’s genes did not return to their original state.
Apparently, journalists in Russia and the West have drawn wrong conclusions from the results of the NASA study and therefore misled their readers. As has found out edition of The Verge, in fact, changes in the genetic code astronauts do not carry serious consequences, and it still is a twin with his brother Mark.
The idea of the project “Gemini” was to send one of the brothers into space, and leave the other as a control sample on Earth. So the experts wanted to find out how the human body will change after a long stay in space with the example of two identical people.
Scientists have found out that Scott Kelly has changed the bacteria content in the intestines, the density of bones and increased telomeres at the ends of chromosomes, although in ordinary people on Earth they decrease with age. However, 7% of the genetic code of the astronaut has not changed forever.
The fact is that human DNA can change under the influence of certain factors, for example, because of smoking cigarettes or ultraviolet radiation. In a study of twins NASA discovered “hundreds of unique mutations” in the genome of Scott and Mark, some of them found after the return of one of the astronauts to Earth. The space agency concluded that these changes could be caused by stress from travel in space or changes that occurred before, but not detected in time.
Nevertheless, there is nothing strange about mutations in Kelly’s body. According to Dan Arking, a professor of medicine at Johns Hopkins University, mutations occur on Earth all the time and become more frequent when a person grows old.
If you put someone in a stressful and changing environment, their gene expression will change. If you live long at high altitude, you will see a change in your own gene expression: you will have more blood cells in your blood.
In fact, NASA has discovered changes in the expression of Kelly genes-the process of transferring genetic information from DNA to proteins and polypeptides via RNA. This process is not associated with a change in the genome itself: the astronaut’s DNA has remained unchanged.
The scientists found out that Kelly had significant changes in gene expression, but her level was almost completely normal after coming to Earth. However, 7% of the indicators of normal expression, even after two years remained slightly modified. These genes were associated with the immune system, the restoration of DNA, the formation of bones and not only. NASA calls these genes “cosmic.”
Changes in 7% of gene expression after space flight do not mean that 7% of DNA has changed or that these changes are necessarily associated with mutations.
As noted in The Verge, apparently, the media misunderstanding happened because of the January press release from NASA, in which the agency used an unclear wording. Those who do not understand genetics could decide that 7% of Scott’s genes have changed due to space. However, in fact, the astronaut RNA has undergone changes.
These two are still identical twins. They had different mutations before and after the flight, and Scott experienced changes in his RNA, not DNA. But their DNA is still the most identical and much more similar to each other than to any other people on Earth or in space.
In a conversation with the publication, NASA confirmed that Scott Kelly’s DNA had not undergone any major changes.
The researchers found only that the changes were in gene expression – this is how your body reacts to the environment. It seems that these indicators are within the range for people during stress, such as mountaineering or diving.
In the near future, NASA promised to publish more detailed research results.