A New Study Unveils the Mind-Blowing ‘Twisters’ Inside Egg Cells
"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links."
Egg cells are our largest cells. They are so large, in fact, that they should have problems distributing proteins and nutrients within themselves.
A new study analyzing this little-understood cellular transport discovered that the egg cells have an ingenious method of leveraging structures within the cell to create mini-twisters that help speed up cellular transport.
Using open-source computational models of a fruit fly oocyte, researchers were able to recreate these life-creating eddies in action.
The egg cell lies at the very foundation of all life on Earth. In humans, an immature egg cell, or oocyte, develops into a mature ovum. Other forms of life use a similar process to produce their own offspring. However, aside from their life-creating properties, oocytes are different from other cells due to their transparent size. While they vary immensely among species, the human egg cell is roughly 150 micrometers in diameter, which is just barely noticeable to the naked eye—a pretty impressive size for structures usually consigned to the world of the microscopic.
This large size is also a bit of a mystery, because unlike other, smaller cells, egg cells should be too big to effectively distribute proteins and nutrients. A small protein could travel the entire length of a typical human cell in 10 to 15 minutes. But a similar trip in an egg cell would take almost a day—far too long to maintain cellular health.
To solve this mystery, computational scientists at the Simons Foundation’s Flatiron Institute—as well as collaborators from Princeton and Northwestern universities—used advanced computer models to analyze fruit fly oocyte cells, and discovered that these cells create minuscule “twisters” using cellular components to help aid microbe transport throughout the cell. The results of the study were published in the April issue of Nature Physics.
“Our findings represent a big leap in this field,” co-author Michael Shelley, a director of the Flatiron Institute’s Center for Computational Biology, said in a press statement. “We were able to apply advanced numerical techniques from other research that we’ve been developing for years, which allow us a much better look at this issue than has ever been possible before.”
Using an open-source program designed to study biophysics, the team discovered that structures known as “microtubules”—flexible filaments that are a major component of an egg’s cytoskeleton—and specialized proteins designed to carry specific molecules worked in tandem to create these miniature eddies. The simulation revealed that when these workhorse proteins exert forces on the surrounding microtubules, the microtubules bend in response. This buckling motion causes fluid to move and influences surrounding microtubules to behave similarly, creating nutrient-dispersing whirlpools in the process.
“Our theoretical work allows us to zoom in and actually measure and visualize these twisters in 3D,” study co-author and Flatiron Institute research scientist Reza Farhadifar said in a press statement. “We saw how these microtubules can generate large-scale flows just through self-organization, without any external cues.”
This microtubule-induced flow is particularly effective at speeding up cellular transport. The scientists estimate that it cuts down transcellular travel time from 20 hours to just 20 minutes. And these tempestuous flows are central to the future organism’s viability, as one researcher commented that “if you destroy the flow in the oocyte, the resulting embryo doesn’t develop.”
While this study reveals the overarching mechanism of how oocytes move microbes from point A to point B, the work also leads to new questions about how molecules are mixed inside the cell. As centuries of science has shown again and again, nature finds a way to overcome seemingly impossible challenges—but it’s up to us to spot those solutions.
You Might Also Like
