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Cannibal worms spare their own brood

Pristionchus nematodes are predators of other worms and also cannibals but a self-recognition system protects their progeny and close kin from this behaviour. This image shows a P. pacificus predator about to eat the larvae of another nematode species. Picture by Jürgen Berger / MPI for Developmental Biology

New caesar research group investigates self-recognition systems in nature

Bonn, January 21st, 2021. Cannibalism is a brutal behavior that occurs in nature regularly. The nematode Pristionchus pacificus devours whatever gets in front of its teeth. This includes other nematodes, and even members of its own species.

Neurobiologist Dr. James Lightfoot is fascinated by these animals, which are only about 1 mm in size. In his experiments with the predatory worms, he made a surprising discovery. Although P. pacificus is not choosy when it comes to its prey, the predator spares its own offspring. How does such a simple organism, whose whole nervous system has only about 300 neurons, manage the complex task of distinguishing its own descendants from other worms?

Dr. Lightfoot will focus on this question at caesar, starting in February 2021. His new group, which is called “Self-recognition and cannibalism”, will focus on the self-recognition system in P. pacificus. “Through our research, we hope to better understand the basic principles and molecular mechanisms behind self-recognition behavior,” Lightfoot says. That’s because, he says, despite the many self-recognition systems already known in nature, surprisingly little is known about the molecular and physiological mechanisms behind these systems, especially when it comes to their role in behavior.

The phenomenon of biological self-recognition has fascinated scientists for decades. It is ubiquitous in nature, and involved in a wide variety of different processes. The spectrum is broad: Self-recognition controls competitive and cooperative behavior in animals, but is also found in the most basic processes including the immune response in vertebrates. Self-recognition systems are also thought to have been essential to evolution, as single-celled organisms became multicellular organisms.
The self-recognition system of P. pacificus has not been observed in any other nematode to date. Using molecular, genetic and neurobiological tools, Dr. Lightfoot and his team will investigate the self-recognition system from the genetic to the behavioral level. Their advantage: nematodes are ideally suited as model organisms for neurobiological research due to their low anatomical complexity.

Dr. Lightfoot is excited to commence his work: “At caesar, I am looking forward to the extraordinary neurobiological expertise of my colleagues and the excellent facilities available. We can make good use of both for research into the self-recognition system.”

Press contact
Sebastian Scherrer
Center of Advanced European Studies and Research,
D-53175 Bonn, Germany.