Tiny Sea Creatures Caught ‘Talking’ to Their Colony Mates todayheadline

In a discovery that challenges our understanding of social behavior, researchers have found that tiny single-celled organisms can coordinate their actions through electrical signals – much like the nerve cells in our own bodies. The finding, published January 8 in Science Advances, reveals sophisticated communication systems in one of the simplest forms of life on Earth.

The study focuses on choanoflagellates, microscopic aquatic organisms that are the closest living relatives to animals. These creatures can exist either as individual cells or form small colonies, making them valuable subjects for understanding how single cells first began working together to form complex life.

“We found communication among the cells of the colonies, which regulates shape and ciliary beating across the rosette,” says Jeffrey Colgren, the study’s lead author from the University of Bergen’s Michael Sars Centre. “When we put them under the microscope, it was very exciting.”

Using innovative genetic tools, the research team observed that cells within choanoflagellate colonies synchronize their movements through voltage-gated calcium channels – the same type of molecular machinery that neurons and muscle cells use to communicate. This discovery suggests that the basic building blocks for coordinated movement existed before the evolution of the first animals.

A Window into Evolution

The study focused on a species called Salpingoeca rosetta, which can transform from single cells into rosette-shaped colonies. These colonies don’t have specialized cells like those found in animals, but the research reveals they’re far from simple clusters of independent cells.

The team discovered that colony members can transmit signals to each other, allowing them to coordinate swimming movements and change shape in unison. This coordination is particularly pronounced in stable rosette colonies, where up to 63% of cellular responses were synchronized across the entire group.

“S. rosetta is a powerful model for investigating the emergence of multicellularity during animal evolution,” explains Pawel Burkhardt, the study’s senior author. “Since our study reveals that colonial choanoflagellates coordinate their movements through shared signaling pathways, it offers fascinating insights into early sensory-motor systems.”

From Simple to Complex

The research team used a fluorescent calcium sensor to watch signals spread between cells in real-time. They observed that when one cell detected a stimulus, it could trigger a wave of activity across the entire colony. This coordinated response involved both electrical signaling and physical changes in cell shape.

Perhaps most intriguingly, the researchers found that different types of colonies showed varying levels of coordination. Rosette colonies, which are more stable, displayed higher levels of synchronized behavior compared to chain colonies, which are more temporary arrangements. This suggests that stronger cellular connections may have been an important step in the evolution of complex multicellular life.

Future Implications

This research opens new avenues for understanding how complex nervous systems evolved from simpler cellular communication networks. The tools developed for this study will allow scientists to further investigate how signals move between cells and whether similar mechanisms exist in other species.

“The tools developed and findings from this study open up a lot of new and interesting questions,” says Colgren. “We’re really excited to see where ourselves and others take this in the future.”