Unlike information released in January, it is not the genes of astronaut Scott Kelly that have been modified after his long journey into space, but its gene expression, says NASA, which recently changed its statement.
Two years after US astronaut Scott Kelly returned to shore for 340 days in orbit, NASA is continuing research on genetic modification. Scott Kelly has a twin brother, Mark. Also an astronaut, Mark spent only 54 days in space, much less than Scott. Since March 2016, the two brothers are the subject of a unique study that involves comparing their DNA.
On January 31, 2018, NASA issued a statement in which it briefly stated that Scott's DNA had been changed by about 7%, compared to his brother Mark. But this information has been misinterpreted. In reality, it is not Scott's genes that have changed, but rather the expression of these, says the space agency, which changed its publication on March 15.
"Very minimal" changes
"Scott's DNA has not fundamentally changed, researchers have only observed changes in gene expression, the way your body reacts to your environment." This is likely to produce for humans in the setting of stress, mountaineering or scuba diving, "say the scientists at the space agency, which indicate that this change of expression is" very minimal ".
By conducting a more in-depth study of the DNA of these twins, NASA researchers found several genetic parameters in Scott, which were not found in his brother Mark. "Some were temporary and only appeared when they were in space, while others lasted longer," they say.
Shortly after his return to Earth, Scott measured for example a few inches longer than Mark. But this phenomenon, which proved temporary, was due to a stretching of his spine caused by exposure to a low-gravity environment, and thus had no connection with his genes.
Better understand the effects of the environment on the human body
Space medicine did not wait until 2017 to look at the changes brought about by space flights and stays. But if these results are as interesting as it is that they are the first, in this field of research, obtained on twins. Twins have always fascinated researchers and doctors.
To be able to study human beings in all identical points, even in the smallest bases of their DNA, is indeed more than precious. The work done on twins thus helps to better understand the effects of the environment on the human body.
"We are at the beginning of our understanding of how spaceflight affects the molecular level of the human body," say scientists NASA and other researchers who collaborate on these studies. These should announce more complete results on Kelly twin studies this summer.