Wave of Blue Fluorescence Reveals the Science of Death in Worms

Researchers have learned a little bit more about the science of death. They've witnessed the final biological events in the life of a worm, watching a wave of blue fluorescence light the way during the creature's final moments.

Relatively little is known about how death spreads throughout an entire organism at the end of its life. Deaths of individual cells trigger a chemical chain reaction leading to the breakdown of cell components and a build-up of molecular debris, but how this reaction spreads is a mystery. That's why scientists turned to worms in order to study the process of death a bit further.

In worms, you can easily see the spread of death as a wave of blue fluorescence travelling through the gut of the creature. By examining this process a bit more closely, the researchers found that this fluorescence is caused by a cell death pathway called necrosis; its spread is dependent on calcium signaling.

"We've identified the chemical pathways of self-destruction that propagate cell death in worms, which we see as this glowing blue fluorescence travelling through the body," said David Gems, one of the researchers, in a news release. "It's like a blue Grim Reaper, tracking death as it spreads throughout the organism until all life is extinguished."

The researchers didn't just watch death, though; they also tried to halt it. By blocking the pathway, they found that they could delay death induced by a stress, such as infection. However, they couldn't stop death from old age, which suggests that aging causes death by a number of processes that act at once.

The mechanisms involved in the worm death are similar to those active in mammals. This means that a worm can, in fact, be a useful model for understanding cell death and how to prevent it.

"Together, the findings cast doubt on the theory that aging is simply a consequence of an accumulation of molecular damage," said Gems in a news release. "We need to focus on the biological events that occur during aging and death to properly understand how we might be able to interrupt these processes."

The findings are published in the journal PLOS Biology.