Can scrambled eggs unscramble themselves? Well, sort of. The cytoplasm of ruptured Xenopus frog eggs spontaneously reorganizes into cell-like compartments, according to a study by researchers.
"We were gobsmacked the senior author."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."
Remarkably, the self-assembled compartments retain the ability to undergo division and can form smaller compartments. Previous studies have shown that some subcellular structures, such as centrosomes and endoplasmic reticulum, can self-assemble outside cells from their purified components, demonstrating that these structures have some ability to self-organize. However, the new study provides the first example of self-organization at the scale and complexity of entire cells.
While studying a molecular process known as programmed cell death, the authors noticed the nuclei in a tube of cytoplasmic extract from frog eggs were behaving unexpectedly. After 30 minutes or so, the nuclei had organized so the distance between two nuclei was almost equal, the lead author said. When they imaged the cytoplasmic extract on microscope slides, they saw that it had formed distinct compartments that resembled 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," the author said. These cell-like compartments formed whether or not Xenopus sperm nuclei were added, suggesting that the behavior relied on something intrinsic to the egg.
To understand the mechanism underlying the phenomenon, the researchers tested whether compartment formation was affected by the addition of chemical inhibitors to cytoskeletal proteins, motor proteins and kinases, which activate other proteins. This approach revealed that ATP, the primary source of energy in the cell, and microtubules, cytoskeletal filaments that provide structural support, were required for compartments to form. Dynein, a type of motor protein, was also required for proper microtubule localization.
These cell-like compartments not only looked like cells; they divided like them, too. The egg extract that the researchers used when they identified compartment formation contained a chemical that prevented the cells from entering the cell cycle. When this chemical was removed, and sperm nuclei were added, the egg extract formed compartments that divided into smaller compartments.
The researchers saw that these compartments could undergo over 25 rounds of division, indicating that the process was very robust. The division was also reductive, since the total amount of cytoplasm remained constant and was being divided into smaller and smaller compartments with each cycle. "You're taking the material from the egg, and it divides in a mode that's reminiscent of embryonic development," the lead said. "Just like they're supposed to in a real egg."
All of these findings suggest that the Xenopus egg cytoplasm has the intrinsic ability to generate the basic spatial organization of the cell and even has some of its functions. An open question, however, is what role this phenomenon plays in the normal physiology of the egg. Another question is whether this ability to self-organize is peculiar to eggs or is shared by other types of cells.
The researchers also hope to further understand what's needed for self-organization to occur. "My favorite question right now," the senior author 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?"
https://science.sciencemag.org/content/366/6465/631
Cell like structures from cytoplasm!
- 2,982 views
- Added
Edited
Latest News
Complete vascularization of…
By newseditor
Posted 28 Mar
Immune cells identified as…
By newseditor
Posted 28 Mar
TB blood test which could d…
By newseditor
Posted 27 Mar
Propionate supplementation…
By newseditor
Posted 27 Mar
Role of human Kallistatin i…
By newseditor
Posted 26 Mar
Other Top Stories
Exposure to farm microbes protect against childhood asthma
Read more
Artificial intelligence to predict customized anti-cancer drug effi…
Read more
Antibody-mediated weight reduction in obese humans
Read more
Neuronal Autophagy Regulates Presynaptic Neurotransmission
Read more
Brain gene that controls food cravings, desire to exercise identified!
Read more
Protocols
Spatial proteomics in neuro…
By newseditor
Posted 28 Mar
All-optical presynaptic pla…
By newseditor
Posted 23 Mar
Epigenomic tomography for p…
By newseditor
Posted 20 Mar
A mouse DRG genetic toolkit…
By newseditor
Posted 17 Mar
An optogenetic method for t…
By newseditor
Posted 13 Mar
Publications
A microfluidic platform int…
By newseditor
Posted 28 Mar
Salmonella manipulates macr…
By newseditor
Posted 28 Mar
BHLHE40/41 regulate microgl…
By newseditor
Posted 28 Mar
Balancing neuronal activity…
By newseditor
Posted 28 Mar
OSBP-mediated PI(4)P-choles…
By newseditor
Posted 28 Mar
Presentations
Hydrogels in Drug Delivery
By newseditor
Posted 12 Apr
Lipids
By newseditor
Posted 31 Dec
Cell biology of carbohydrat…
By newseditor
Posted 29 Nov
RNA interference (RNAi)
By newseditor
Posted 23 Oct
RNA structure and functions
By newseditor
Posted 19 Oct
Posters
A chemical biology/modular…
By newseditor
Posted 22 Aug
Single-molecule covalent ma…
By newseditor
Posted 04 Jul
ASCO-2020-HEALTH SERVICES R…
By newseditor
Posted 23 Mar
ASCO-2020-HEAD AND NECK CANCER
By newseditor
Posted 23 Mar
ASCO-2020-GENITOURINARY CAN…
By newseditor
Posted 23 Mar