Rosette-shaped colonies of the choanoflagellate Salpingoeca rosetta can coordinate their movements using calcium ions (magenta), providing insight into the early evolution of animal nervous systems.
The rise of multicellularity paved the way for the evolution of complex life on Earth. By developing cells with specialized roles, animals and other multicellular organisms were able to grow larger and interact with their environments in unique ways.
Communication between specialized cells in neurons and muscles, for example, underlies the complicated sensory-motor systems that move our bodies around.
But choanoflagellates—tiny, aquatic creatures considered to be the closest living relatives of animals—appear to blur the boundary between unicellular and multicellular life.
Some species, including Salpingoeca rosetta, can exist as individual cells or come together in small, rosette-shaped colonies.
These colonies form through cell division, just like animal embryos, and although they lack specialized cell types, they don’t quite behave like groups of independent organisms either.
These microscopic sea creatures coordinate their movements using electrical signals. This synchronized behavior, which is somewhat reminiscent of a school of fish moving in unison, mimics the cell-to-cell communication seen in animal nervous systems—potentially providing key insights into the evolution of multicellularity.
To investigate the behavior of S. rosetta colonies, scientists genetically engineered the choanoflagellates to express a fluorescent sensor that glows in the presence of calcium.
They found that the cells were using voltage-gated calcium channels—the same channels that neurons use to communicate with muscle cells—to transmit signals and synchronize their behavior, allowing them to coordinate swimming movements and change shape in unison.
* Tiny microbe colonies communicate to coordinate their behavior
Dated: 15 Jan 2025
Source:
https://www.eurekalert.org/news-releases/1069850---
This regulated flow of information between cells in a colony “ demonstrates cell-cell signaling at the cusp of multicellularity.”
The team also discovered that certain choanoflagellate colonies were better at synchronizing their movements than others
* Electrical signaling and coordinated behavior in the closest relative of animals
Dated: Jan 15, 2025.
Source:
https://pubmed.ncbi.nlm.nih.gov/39772683/