NOV 18, 2019 2:50 PM PST

Cell-Like Structures Form Out of Frog Egg Cytoplasm

WRITTEN BY: Carmen Leitch

Xenopus is a type of frog that is commonly used as a model organism in biological research, and their eggs develop outside of the body, making them especially good for studying development. Researchers have found that if ruptured, Xenopus eggs can reorganize spontaneously into compartments that resemble cells. The findings, by researchers at Stanford University, have been reported in Science.

"We were gobsmacked," said James Ferrell, M.D., Ph.D., the senior study author, and professor of chemical and systems biology and of biochemistry. "If you blend a computer, you'd end up with tiny bits of computer, and they wouldn't even be able to add two and two. But, lo and behold, the cytoplasm reorganizes."

After reassembling themselves, these compartments can continue to go through rounds of division and can generate smaller compartments. While some subcellular organelles, like the endoplasmic reticulum, are known to be capable of self-assembly outside of cells, this is the first time researchers have observed reorganization in larger structures.

Lead study author and postdoctoral scholar Xianrui Cheng, Ph.D. was studying programmed cell death, a common biological process. He saw that cytoplasm extracted from frog eggs was doing something unusual; nuclei were arranging themselves so there was equal distance between them. Cheng said that he placed the extract on slides and imaged them, and observed that it generated compartments that looked like a sheet of cells.

"If you take the cytoplasm of the frog egg -- note that the cytoplasm has been homogenized, so whatever spatial structure that was there has been completely disrupted -- and just let it sit at room temperature, it will reorganize itself and form small cell-like units. That's pretty amazing," Cheng said. These compartments were created regardless of whether sperm nuclei were added; something about the egg gave them this ability.

The scientists delved into the mechanism behind this phenomenon and determined that the cell's molecular fuel, ATP, and structural filaments called microtubules, were essential, as was a motor protein that helps the microtubules get where they need to go, called dynein.

The researchers also learned that if a chemical that prevents the cell cycle from starting was removed, and nuclei from sperm were added, the compartments could divide into smaller ones. The compartments could go through over 25 rounds of division, creating compartments of decreasing size (seen in the video).
"You're taking the material from the egg, and it divides in a mode that's reminiscent of embryonic development," Cheng said. "Just like they're supposed to in a real egg."

The cytoplasm of Xenopus eggs appears to have an inherent ability to create spatial organization, although researchers don't know its role in normal physiology, or whether other kinds of cells, not just egg cells, are capable of the same process.

The scientists want to learn more about this self-organization. "My favorite question right now," Ferrell said, "is can we make a simple model that explains the basics of this organization process? Or do we have to do something extremely complicated, like account for every single thing that we know a microtubule can do?"

Sources: Science Daily via Stanford Medicine, Science

 

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
SEP 08, 2020
Neuroscience
Thyroid Inflammation Linked to Anxiety Disorder
SEP 08, 2020
Thyroid Inflammation Linked to Anxiety Disorder
Findings from a new study suggest that people with autoimmune inflammation in their thyroid may be more likely to develo ...
SEP 20, 2020
Cell & Molecular Biology
Revealing the Structure of Hallucinogens Bound to Their Receptor
SEP 20, 2020
Revealing the Structure of Hallucinogens Bound to Their Receptor
Recent studies have demonstrated that hallucinogenic drugs like LSD, psilocybin, and mescaline have therapeutic potentia ...
SEP 25, 2020
Cell & Molecular Biology
Researchers Take Organoids a Step Further
SEP 25, 2020
Researchers Take Organoids a Step Further
The human body is made of many different kinds of cells, which can often be cultured in a lab and studied. However, thos ...
OCT 14, 2020
Neuroscience
Researchers Pinpoint Neurons Affected by Epilepsy
OCT 14, 2020
Researchers Pinpoint Neurons Affected by Epilepsy
Video: Explains in more detail the different receptors affected by epilepsy. Researchers at the University of Copenhagen ...
OCT 26, 2020
Cancer
Investigating the Receptor Protein FPR1 in Brain Cancer
OCT 26, 2020
Investigating the Receptor Protein FPR1 in Brain Cancer
Amongst the more common targets for cancer therapies are cell surface receptors. These receptors are proteins – us ...
NOV 23, 2020
Cancer
Platelets May Protect Cancer Against PD-1 Therapies
NOV 23, 2020
Platelets May Protect Cancer Against PD-1 Therapies
One of cancer’s greatest tools is its ability to manipulate the immune system. Many cancer therapies have arisen t ...
Loading Comments...