Space worm tests show microgravity can alter genes

Nov. 25 (UPI) -- After a tour on the International Space Station, a group of nematode worms exhibited changes in nearly 1,000 genes.

The findings, published Wednesday in the journal iScience, suggests prolonged exposure to microgravity can influence cells at the genetic level.

Though most of the genetic changes identified by scientists were relatively subtle, researchers also observed a handful of more significant genetic alterations among nervous system cells, or neurons.

The study, a collaboration between the University of Exeter and NASA GeneLab, could help scientists identify the genetic origins of the physiological effects of space travel, highlighted by numerous previous studies.

"We looked at levels of every gene in the worms' genome and identified a clear pattern of genetic change," study co-author Timothy Etheridge said in a news release.

"These changes might help explain why the body reacts badly to space flight. It also gives us some therapy targets in terms of reducing these health effects, which are currently a major barrier to deep-space exploration," said Etheridge, a senior lecturer at Exeter.

Several previous studies have found microgravity can alter the volume and shape of different parts of the brain. Other studies have shown microgravity exposure can affect muscles, heart cells and the intestines.

For the latest experiment, researchers sent several dozen Caenorhabditis elegans worms to the space station, where they were exposed to microgravity for several weeks. Another group stayed on Earth and was exposed to high gravity inside centrifuges.

The high-gravity experiments helped accentuate the genetic effects of microgravity, while also offering scientists the chance to consider the potential of high-gravity interventions in space.

"A crucial step towards overcoming any physiological condition is first understanding its underlying molecular mechanism," said lead author Craig Willis.

"We have identified genes with roles in neuronal function and cellular metabolism that are affected by gravitational changes," said Willis, a doctoral student at Exeter.

The molecular and physiological changes observed in the space worms were similar to those previously observed in astronauts.

"So our findings should provide foundations for a better understanding of spaceflight-induced health decline in mammals and, eventually, humans," Willis said.