MAR 14, 2018 03:58 PM PDT

Gaining Insight Into Death Through Worm Rigor Mortis

WRITTEN BY: Carmen Leitch

Researchers have found that worms experience rigor mortis before, rather than after death as humans do. The study is the first to observe rigor mortis in worms and provides a little insight into the biological processes experienced by an organism when it dies. The international team of scientists from Washington University and UCL used the C. elegans roundworm to learn a bit more about death from old age, something that is not well understood. Their findings have been reported in Cell Reports.

This is cellular necrosis in C. elegans. / Credit: David Gems, UCL

"Cell death has been widely studied but much less is known about [the] death of whole organisms, how it happens, what triggers it, and when it begins and ends. But it's extremely important for understanding fatal diseases in humans, especially those caused by aging," said research leader Professor David Gems of the UCL Institute of Healthy Aging.

Death is defined by a lack of heart or brain function; when it ceases, an organism is considered dead. But there are many physiological events before and after death. In C. elegans, cell death spreads through the animal. As a cell dies, it triggers the death of neighboring cells by releasing calcium. The process starts with muscles, causing hypercontraction and rigor mortis.

"The way death spreads from cell to cell by calcium is like a house burning down," explained lead author Dr. Evgeniy Galimov, of the UCL Institute of Healthy Aging.

When a person dies, stiffness sets in. That rigor mortis in followed necrotic degeneration and muscles get soft again. That process is a consideration in the meat industry; the product has to be tender. It can also help forensic studies that seek to establish a time of death. C. elegans undergo a similar series of contraction and relaxation in their muscles as they die.

"What really surprised us at first was that rigor mortis in worms begins while they are still alive. But then we realized that death from circulatory failure, as in mammals, doesn't happen in C. elegans. The worms are so small they don't need a circulatory system to get oxygen for respiration," explained Dr. Galimov.

"Dying C. elegans also undergo what we term a 'belly punch' phenomenon where death contraction in the head drives the pharynx backward into the intestine, and the impact triggers cell death," noted Professor Gems.

This work, which you can learn more about from the video above, suggests that declines that are a hallmark of old age may be due to an inability to generate cellular fuel, ATP. That leads to a failure to contain calcium within the cell. When it is released, it causes cellular necrosis. 

"Discovering rigor mortis in worms is exciting as it highlights a key step in the chain of events leading from healthy adulthood to death from old age. It helps us to understand death in humans, and perhaps in the future to prevent death in mortally ill patients," concluded Professor Gems.


Sources: AAAS/Eurekalert! Via University College London, Cell Reports

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
OCT 23, 2019
Genetics & Genomics
OCT 23, 2019
Do You Inherit Your Morals?
Morality is usually a subject discussed by philosophers, not biologists. But is it really a purely philosophical issues? After all, what makes us more susc...
OCT 23, 2019
Cell & Molecular Biology
OCT 23, 2019
A New Approach to Tick Control
Ticks can transmit a long list of diseases to humans and other animals, and more are emerging all the time....
OCT 23, 2019
Neuroscience
OCT 23, 2019
New MRI scan can reveal molecular changes in the brain
MRI scans give us pictures of the brain that depict the physical structure of brain tissue. Now, researchers discovered a way to determine the biological m...
OCT 23, 2019
Cell & Molecular Biology
OCT 23, 2019
How Proteins Send Instant Messages
Our cells use proteins as messengers that send or receive critical signals to carry out the functions essential for life....
OCT 23, 2019
Neuroscience
OCT 23, 2019
Sea Slugs Reveal a Link Between Food Comas and Memory
A recent study suggests that there may be a connection between food comas feeling tired after eating and long-term memory formation. This f...
OCT 23, 2019
Neuroscience
OCT 23, 2019
Scientists Create Memory of Courtship Song in Zebra Finches
A new study published in Science shows how a neural circuit in Zebra finches, involved in forming the learning of a courtship song, can be manipulated.&nbs...
Loading Comments...