The perfect lab animal is strikingly, surprisingly beautiful

In 1963, on a hunch, a South African biologist named Sydney Brenner decided to study a species of worms named C. elegans.

The worms turned out to be the perfect lab animal. They were simple creatures that lived in the dirt and ate bacteria but were just complicated enough to provide biological insights applicable to human health. C. elegans was the first organism to have its genome sequenced and, aside from humans, have been sent into space more than any other animal.

In 2002, Brenner, along with Robert Horvitz and John Sulston, won the Nobel Prize in Physiology or Medicine for their work describing how cells deliberately kill themselves for the greater good of the whole worm. The same process occurs in human cells as well — most famously in a webbing of skin that would otherwise span our fingers. Investigating normal cell death has helped scientists understand cancer — a disease where cells continue to grow and divide when they should not.

Brenner’s hunch continues to pay off. Current studies with worms are helping us understand how our minds work and how we age.

Eugene Lee, a graduate student in the Horvitz laboratory located on the campus of the Massachusetts Institute of Technology, is using C. elegans to describe how nerve cells work together to give rise to complicated behavior and consciousness. Along the way, he’s spent countless hours examining striking images of a strange microscopic world where the flick of a worm’s tail or an unusual patch of glowing cells could be the next key breakthrough.

A strain of C. elegans expressing a fluorescent protein in cells. Small dots of fluorescence indicate that proteins have concentrated in the nucleus. Scientists have genetically engineered strains of C. elegans to produce fluorescent proteins. The patterns of fluorescence help researchers understand how cells and worms are reacting to stressful situations.

Most C. elegans are hermaphrodites that possess both female and male organs. Males are rare and no females exist. During its life cycle, a typical hermaphrodite lays about 300 eggs.

Scientists are studying the worm nervous system to explain animal behavior. Understanding how and why a worm responds to certain stimuli, like laying eggs in response to bright light, can be tricky. “I actually try to imagine myself as a worm,” said Lee. “We do it all the time in lab.”

Because they are easy to raise in large numbers, worms are useful for drug screens — enormous experiments where scientists test how C. elegans responds to hundreds of different chemicals. Here worms stiffen when exposed to Prozac.

Researchers have a relationship with worms that is at once reverent, clinically distant, intimate, and obsessive. Over several decades, scientists have identified and mapped the development of all 959 cells in adult hermaphrodites and 1031 cells in adult males. Brenner called C. elegans “nature’s gift to science.”