NASA's first twin experiment showed changes in DNA in space

Scientists will need a lot of time to understand this change.

Scott and Mark Kelly are NASA astronauts and also twins with identical DNA. NASA's first "twin study" in recent times analyzed countless samples of their blood and saliva. According to the first findings published by NASA, under the influence of the environment appeared a difference between the couple's DNA. But understanding those changes can take a long time.

These twins are like treasures to scientists. Because they carry within themselves the exact same genetic nature, scientists can use them to study how the environment interacts and affects human DNA.

Astronauts Scott Kelly and Mark Kelly of NASA.

Between 2015 and 2016, Scoot Kelly spent nearly a year - 340 days - in a zero-gravity environment on the International Space Station ISS. In the meantime, Mark's twin brother will live on Earth, subject to gravity. To find out how a year in space affects the body, NASA researchers began tracking the duo, at which point Scott would constantly be out in space.

After analyzing detailed data, the researchers noticed the difference, the length of the telomeres (repetitive sequences of DNA at the end of chromosomes) grew slightly longer when Scott was in outer space, but quickly shrunk to normal size after returning to Earth. During that time Mark's telomeres also began to shorten. In addition, there are some changes in their DNA. The amount of methylated DNA (methyl groups added to DNA sequences that alter the function of the DNA fragment without changing its sequence) in Scott decreased while in outer space, while Mark increased. .

But the question is what led to this change? According to the report of Nature (a multidisciplinary scientific journal), the level of DNA methylation back to equilibrium once the astronauts return to Earth is quite normal, because they have undergone rapid changes. fast on the diet (no longer frozen, dry meals) and sleep behavior (in bed, affected by gravity). However, scientists still do not understand why the telomere length of the twins has changed and has the corresponding effects on each person's health.

The next stage is to find out which changes stem from space flight and which changes are only the result of normal aging. To find the answer, scientists need to conduct more research on twins, wide and multidimensional. Statistically, the larger the sample size, the more conclusions it will come up with.

Therefore, we will have to wait for NASA to research a large number of twins in order to fully publish future results.

1. The height of astronauts increased 5cm after 1 year of living in space
2. The pain of ISS astronauts returning to Earth