Space Worms Live Long and Prosper

A microscopic worm used in experiments on the space station not only seems to enjoy living in a microgravity environment, it also appears to get a lifespan boost.

This intriguing discovery was made by University of Nottingham scientists who have flown experiments carrying thousands of tiny Caenorhabditis elegans (C. elegans) to low-Earth orbit over the years. But why are these little worms so special?

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C. elegans may be microscopic, but they were the first multi-cellular organism to have their genetic structure completely mapped. These little guys possess 20,000 genes that perform similar functions as equivalent genes in humans. Of particular interest are the 2,000 genes that have a role in promoting muscle function. As any long-duration astronaut can attest, one of the biggest challenges facing mankind's future in space is muscle atrophy.

Understanding how C. elegans function in space is therefore of huge scientific value not only for tiny worm enthusiasts, but for the manned exploration -- and colonization -- of space.

In 2011, Discovery News reported on some results to come from the C. elegans experiments. Nathaniel Szewczyk, of the Division of Clinical Physiology at the University of Nottingham, discussed the worms' microgravity reproduction habits and, as it turns out, C. elegans prospered just fine. Over three months, Szewczyk's team were able to observe the space worms flourish over twelve generations.

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And now, in results published on July 5 in the online journal Scientific Reports, it appears that C. elegans not only adapted to microgravity conditions, their lifespans also received a boost when compared with their terrestrial counterparts.

"We identified seven genes, which were down-regulated in space and whose inactivation extended lifespan under laboratory conditions," Szewczyk said in a press release. This basically means that seven C. elegans genes usually associated with muscle aging were suppressed when the worms were exposed to a microgravity environment. Also, it appears spaceflight suppresses the accumulation of toxic proteins that normally gets stored inside aging muscle.

But the biological mechanisms behind this anti-aging effect are a bit of a mystery.

"It would appear that these genes are involved in how the worm senses the environment and signals changes in metabolism in order to adapt to the environment," added Szewczyk. "For example, one of the genes we have identified encodes insulin which, because of diabetes, is well known to be associated with metabolic control. In worms, flies, and mice insulin is also associated with modulation of lifespan."