Worms return from space.

To say that Bob Johnsen was over the moon when he picked up worms at Cape Canaveral in Florida on June 19 is putting it mildly. Once he had his cargo in hand, the Simon Fraser University (SFU) associate researcher headed straight for the lab he shares with David Baillie. Baillie is an SFU professor of molecular biology and biochemistry and is also a Canada Research Chair in genomics.

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The worms (C. elegans) returned from a stay aboard the International Space Station (ISS). Orbiting the earth since 2000, the ISS is continually inhabited by humans and other creatures. Six months at ISS was enough time for these worms to produce 25 generations. The C. elegans is the perfect organism to determine the impact of radiation exposure on humans in space because it is the simplest multi-cellular organism with a completely known genomic DNA sequence. Like humans, C. elegans has about 20,000 genes. About 4,500 of these genes are effectively doing the same jobs in worms as in humans. Worms also make an efficient subject for these experiments because they are only as long as a grain of salt is wide. Their size helps scientists keep down the costs of their experiments in space. It costs about $22,000 a kilogram to send cargo up into space. The total mass of these worms in space is 60 grams.

Thanks to a system that he co-developed as a grad student under Baillie, Johnsen will be able to tell how much the worms have mutated. The device, called eT1, enables scientists to capture and analyze accumulations of mutations, similar to the way scientists analyze growth rings on trees. Normally, worms lose their genetic mutations as they grow.

"Only by analyzing the extent of their genetic mutations will we be able to understand the impact of lengthy exposure to radiation in space," says Johnsen. "Before we can mitigate the impact of radiation, we have to understand the biological changes it causes." Current research indicates that one in eight travellers taking a round trip to Mars could die from radiation poisoning and the rest would likely be very ill. NASA scientists are anxious to know how they can mitigate the impact of radiation because they hope to send a human crew to the moon by 2020 and to Mars by 2055.

Simon Fraser University