Eggs can be hundreds of times larger than average cells, and while this allows them to develop into full-fledged organisms, the flow of nutrients and other molecules within them becomes extremely difficult. the Simmons Foundation I mentioned what's new About searchThey discovered how materials move from one point in the egg to another.
Until now, experts have known that small tornadoes form inside cells, and this vortex carries nutrients with it, but the mechanism that creates the vortexes has only now been discovered. In the context of the research, experiments were conducted on house fly eggs, in addition to computer modeling.
A small tube with kinesin “moving” on it.
Source: Wikimedia Commons
In the average human cell, it takes 10 to 15 seconds for a molecule to spread from one end of the cell to the other. In a small bacterial cell, one second is enough to do this, but in the mouse eggs examined, the diffusion process alone takes one day.
This is a very long time for the cell to function properly. Instead, eddies form in the cell, which, like tornadoes, pick up some objects and then deposit them elsewhere.
The interior of the oocyte is based on modeling, with the movement of microtubules. Source: Simmons Foundation
The researchers alternated experiments and computer simulations, building up what was happening bit by bit. It turns out that the spontaneous, self-organized movement of microtubules on the inner side of the cell wall — long, tube-like structures that perform very diverse tasks in cells — creates the vortices.
If the microtubules bend as a result of the molecular motor moving over them, the fluid filling the inside of the cell begins to move, and this causes neighboring microtubules to bend in the same way, thus forming a vortex. As a result, 20 minutes is enough for nutrients to flow through, which actually meets the needs of cell function.
