How curiosity-driven research in a worm won four Nobel Prizes Premium

Discover the significance of C. elegans in biological research, from Nobel Prize-winning discoveries to insights into gene expression control.

Victor Ambros and Gary Ruvkun won the 2024 Nobel Prize in Physiology or Medicine for discovering microRNAs and their role in controlling gene expression. This pioneering discovery was made using the roundworm Caenorhabditis elegans. This 1-mm long, slender, and transparent nematode has been the star of many pathbreaking discoveries in biology, four of which have won Nobel Prizes.

How did C. elegans, a tiny invertebrate, become such a crucial tool for biological research? What insights did this worm yield? What is the value of such research for society when one can argue that our focus should be on studying human biology?

This is the story of C. elegans. In brief, advances necessary for human health and welfare often arise from solving fundamental biological problems. One major difficulty isn’t just finding the right question to ask but also finding the right place to ask it where it can be solved. C. elegans provides exactly such a setting: a relatively simple but versatile model for biological investigations whose results often reveal general principles that remain valid or have parallels in other organisms, including humans. The worm’s story also highlights how breakthroughs can arise from research driven by curiosity.

In 1963, biologist Sydney Brenner wrote to his peer Max Perutz his thoughts on research in the fields of development and neurobiology. He believed that, as the nature of problems in these areas wasn’t clearly defined, there was a gap in identifying the right experimental approach that would lead to “defining unitary steps of any given process”.

Brenner suggested the use of genetic analysis in defining such unitary steps in both animal development and the nervous system. He also indicated his choice of using a metazoan organism, which was likely to be the roundworm Caenorhabditis briggsae. But Brenner later chose the nematode C. elegans, a close relative of C. briggsae, for a number of reasons such as its small size, short life cycle (~3.5 days), small genome, transparent body, and its small number of 302 neurons — unlike the billions of neurons in the human brain. Additionally, C. elegans has several organ systems akin to those found in humans, allowing a chance to identify principles in development.

Ellsworth Dougherty was among the early scientists to realise and use the potential of free-living nematodes in genetics research. In 1963, Brenner requested Dougherty for a culture of C. elegans and also sought his guidance on its growth conditions. This collaboration sowed the seeds for building a community that shared resources and collectively contributed to advancing biology research. This culture of sharing resources and unpublished information continues to this day.

Brenner shared the 2002 Nobel Prize for medicine with H. Robert Horvitz and John Sulston “for their discoveries concerning genetic regulation of organ development and programmed cell death”. In his award ceremony, Brenner said, “Without doubt the fourth winner of the Nobel Prize this year is Caenorhabditis elegans: it deserves all of the honour but, of course, it will not be able to share the monetary award”.