Astronaut twins study yields new insights for DNA sequencing tools
Long-term spaceflight causes more changes to gene expression than shorter trips, especially to the immune system and DNA repair systems, according to research by Weill Cornell Medicine and NASA investigators as part of NASA’s Twins Study, which followed the only set of identical twin astronauts for more than a year.
Dr. Christopher Mason, an associate professor of physiology and biophysics at Weill Cornell Medicine, led one of 10 teams of scientists chosen by NASA to compare genetic, physiologic and behavioral changes in identical twins Scott and Mark Kelly before, during and after Scott embarked on a one-year mission on the International Space Station from 2015-2016. Mark, who has gone on shorter space missions in the past, stayed behind on Earth, providing a genetically identical control subject.
The findings, which were published in Science and featured on its cover, show that Scott experienced thickening of the carotid artery, thickening of the retina, weight loss, shifts in gut microbes, reductions in cognitive abilities, DNA damage and changes in gene expression, and a lengthening of the ends of chromosomes called telomeres during the flight. Upon return to Earth, the telomere elongation was replaced by accelerated shortening and loss, a potentially negative consequence for cellular health. The study will help scientists better understand the changes astronauts undergo during long-term space travel. It may also help them better treat or prevent any damage to astronauts’ health caused by prolonged spaceflight, particularly as NASA and other groups prepare for three-year missions to Mars.