Optogenetics enables controlled shape-shifting in starfish oocytes

Scientists have used a technique called optogenetics to control the movements and shapes of starfish oocytes, which are eggs in early development. By shining light on these cells, researchers can make them change shape, which could lead to new types of synthetic cells for medical uses like healing wounds or delivering drugs. The team studied how waves within the starfish oocytes generate force and send signals that allow the cells to change shape. They published their findings in the journal Nature Physics. This research offers a new tool to influence how cells look and behave during their development. The key to this process is an enzyme called GEF, found in the cell's cytoplasm. When GEF is activated, it changes the Rho protein, which is crucial for managing how cells move and maintain their shape. This switch to a membrane-bound state allows muscle-like fibers to grow, enabling the cell to contract. The researchers made a special version of the GEF enzyme that responds to light. They injected this into oocytes collected from a single starfish, allowing the cells to produce the light-sensitive enzyme. They then used a microscope and different light patterns to observe how the cells reacted. The experiments showed that targeting the light at specific areas made the GEF enzyme activate and pull the cell into new shapes, like a square. They also discovered that shining light in one spot could cause the cell to contract powerfully, revealing the exciting nature of this cellular system. The scientists created a theoretical framework to predict how the cell will change shape based on light stimulation. This research provides insights into the basic processes of cell development. It could pave the way for creating programmable synthetic cells that could be tailored for specific medical applications in the future.