Amputated Flatworm Regenerated Into Double-Headed Worm While Traveling in Space

Posted on June 13, 2017

Flatworm became double-headed after space travel

Scientists wanted to test flatworms regeneration capabilities in space so they sent an amputated group of planaria on a trip aboard the International Space Station. The researchers wanted to see if the worms would regenerate in space. They were surprised to find that one of the flatworms not only regenerated but grew a second head.

The researchers led by Tufts University scientists launched the flatworms into space via the SpaceX Commercial Resupply Service Mission 5 on Jan. 10, 2015. The flatworms were either left whole or amputated and sealed in tubes filled half with water and half with air. There were also two sets of control worms exposed to the same temperature changes as the space-exposed worms back on Earth.

Researchers discovered that one of the amputated fragments sent to space regenerated into a rare double-headed worm. In more than 18 years of maintaining a colony of D. japonica (involving over 15,000 control worms in just the last five years alone), the Tufts researchers have never observed a spontaneous occurrence of double-headedness until now.

The scientists ran an additional experiment and chopped both heads off the double-headed worm. The headless middle fragment then regenerated into a double-headed worm. The scientists say this demonstrates that the "body plan modification that occurred in the worm was permanent."

The space traveling worms and the stay-at-home worms were all transferred to petri dishes containing fresh spring water. The ten whole worms that had traveled in space curled up and and were partially paralyzed and immobile, before returning to normal after two hours. The finding suggests to the worms had altered their biological state during space travel. The space worms and stay-at-home worms also differed in their reaction to light.

A research paper on the space traveling flatworms was published in the journal, Regeneration.

Image: Tufts University