When an egg is fertilized, billions of proteins ripple out across its surface, producing a dazzling cascade of swirling patterns. These spiraling arcs are a fundamental component of beginning cell division.
“The egg is a huge cell, and these proteins have to work together to find its centre, so that the cell knows where to divide and fold, many times over, to form an organism.” “Without these proteins making waves, there would be no cell division.”
Nikta Fakhri from MIT
These turbulence-like behaviors, the researchers explain in a new study, may be found in both physical and biological matter, at sizes ranging from the cosmic to the infinitesimal: from whirling vortices in planetary atmospheres to bio-electrical signaling in the heart and brain.
While the parallels are many, the nature of their similarity remains a mystery, at least conceptually: “Despite such substantial progress in the understanding of topological defects and their functional implications, it is not yet clear whether statistical laws that govern such topological structures in classical and quantum systems extend to living matter”.
In their starfish experiments, the researchers released a hormone to simulate the onset of fertilization within the oocytes, which caused waves of a signaling protein known as Rho-GTP to ripple across the membrane for several minutes at a time, with the results being imaged under a microscope with the help of fluorescent dyes that bind to Rho-GTP.
The researchers were able to see a lot of whirling spirals coming from the egg’s floor medium by varying the emphasis of the hormone set off.
“In this way, we created a kaleidoscope of different patterns and looked at their resulting dynamics” explains Fakhri.
Not much was known about the dynamics of these surface waves in eggs, and after we started analysing and modelling these waves, we found these same patterns show up in all these other systems. It’s a manifestation of this very universal wave pattern.
Topological turbulence in the membrane of a living cell, Tzer Han Tan, Jinghui Liu, Pearson W. Miller, Melis Tekant, Jörn Dunkel & Nikta Fakhri
Published: March, 2020
https://doi.org/10.1038/s41567-020-0841-9