Twins in space: how space travel affects the expression of genes

Scientists got a rare opportunity to see how the conditions on the International space station affected the gene expression by comparing identical astronauts-twins: one of them had been in space for about a year, the other stayed on Earth. The environment on the space station caused changes in gene expression through a process of epigenetics. NASA scientists already know that the astronauts are different be subjected to physical stress.

Studies of the genetic background of the astronauts can you explain why some are more prone to health problems when returning to Earth. These results can lead to individual preventive measures for vulnerable astronauts. And most amazing of all, these discoveries can also lead to the development of methods to treat any syndromes that affect us on Earth.

What happens to man in space: the example of the twins

NASA is studying the effects of space travel for the human body from the beginning of the space age. At a press conference held about a week after arrival at the International space station (ISS), canadian astronaut David Saint-Jacques said that he felt “somewhat overwhelmed” and “with a big puffy red face, as if hanging upside down on the bar”. That uncomfortable feeling came due to redistribution of fluid from the lower part to the upper part of the body.

The health of astronauts after long missions

Health effects arising from prolonged space flight has not been studied. In General, the astronauts maintain excellent mental and physical health compared with the population, even after returning from long missions. And yet, the consequences of such missions to be recognized scientifically, including problems with the cardiovascular system and vision, the causes of which are studied.

NASA scientists are exploring how gene expression is how DNA is converted into tissue — changes in response to the impact of the environment on the ISS. The area of epigenetics describes mechanisms by which environmental factors such as microgravity, a relatively high level of carbon dioxide and possible fluctuations of radiation, change the way of reading DNA.

They also want to know how the unique DNA of each astronaut will determine their response to the environment of the space station. Now, of the 37 studies, which are conducted on the space station, 3 is devoted to genetic research.

Two sides of the same coin

Preliminary results of exclusive studies of identical twins support the idea that space travel can affect the expression of genes in various organs. From 2015 to 2016 astronaut Scott Kelly aboard the ISS for 340 days in a row. His twin brother mark remains on Earth. The basic genetic code Scott has not changed, but the environment of the space station influenced how the code was transformed in the tissue.

According to one of the leading scientists in the study of twins Christopher Mason, these changes occurred in important biological pathways relevant to the formation of bones and immune system. Changes in expression of genes were classified in relation to the possible risk as “low, medium or high”.

Changes of gene expression with low risk (approximately 93% of all changes) were back to normal when Scott came back to Earth. According to Mason, it is possible to change from medium to high risk has not changed in six months and “for them, they will keep an eye on”. For example, changes of expression, which led to the formulation of the immune system in the mode of “increased readiness”.

Although the study of identical twins provides the best estimate of the impact of outer space for the expression of the genes around is not so much of astronauts-twins.

Confirmation of results in twins, Kelly will require studies from other astronauts. Currently, these studies are conducted to confirm to the International space station, because to analyze going liquid biopsy (cell-free DNA samples and RNA from blood). But experiments on twins served as “a springboard for all subsequent research”, says Mason.

Mission changing opinion

Previous studies of eye health in the group of astronauts suggest that not all astronauts are equally responsive to life on the space station. Ocular syndrome in astronauts is a condition that affects some astronauts. These ocular changes are classified by NASA as “a significant risk to space travelers” and include changes of the crystalline lens and eye shape.

In some cases, astronauts with perfect vision to space flight “returns with the need to wear glasses,” says Scott Smith, a leading biochemist and nutrition at NASA. “We saw chemical changes in the blood samples (from the astronauts) before the flight, so I decided to study the genetics”.

For this study blood samples gave 72 astronaut. The analysis showed that the genetic background of each astronaut plays a role in determining the vulnerability of their eyes or epigenetic reaction to harmful triggers on the space station.

Space eye and the worms of the earth

Research suggests that some of the astronauts can be warned about personal risks of developing problems with your vision during long space flights. Better yet, apply and implement the individual preventive measures for the people with the greatest risk of disease.

“Virtually all of the work NASA has implications for the population as a whole,” Smith said.

Ocular syndrome in astronauts is associated with another, much more common health problem here on Earth. It turns out that the same genetic variants and changes in serum factors that are associated with eye problems the astronauts are also associated with polycystic ovarian syndrome, a form of infertility in women.

Genetic and epigenetic studies on astronauts astronauts will provide personalized medical approaches in space. And they could provide people on the Ground potential treatments of complex diseases. These are the preliminary results of the study.

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