Cell: Observing "how tissues form organs" in the real in-vivo environment for the first time

But how does the cell fold itself into such a complex structure precisely during development? What is the fundamental force that drives this process?

Now, researchers at Harvard Medical School have discovered a mechanical process by which blocks of cells become delicate, circular semicircular canals of the inner ear

The study on zebrafish was published in the journal Cell on December 22

Although this study was carried out on zebrafish, this work reveals the basic mechanism of how tissues form shapes-the researchers say that this mechanism may be conserved in vertebrates, or it may have implications for bioengineering

Transparent model

The study’s senior author Sean Megason (Sean Megason) is a professor of systems biology at the Blavatnik Institute of the Royal College of Medicine in the United Kingdom.

"They are transparent, so we just need to put them under a microscope to observe the entire process from a single cell to a larva that can swim and have all parts," explained Akankshi Munjal, the first author of the study, from the Royal College of Medicine.

These parts include the semicircular canal, the three fluid-filled tubes in the inner ear, which are used for balance and spatial orientation

Munjal said: "This is an exciting opportunity for us to understand how three-dimensional organs are composed of a single piece of simple cells

"The inner ear is a model that illustrates how cells work together to form the complex structures necessary for the function of the organism," Megason added

What they found surprised them

The traditional idea is that actin and myosin act as tiny motors inside the cell, pushing and pulling them in different directions, folding the tissue into a specific shape

Munjal said: "It's like you wear a corset on a water balloon and then transform it into a rectangular structure

"Our work demonstrates a new way of doing things," Megason said, hoping that it will encourage people to consider other mechanisms that might participate in the formation of an organization

Megason and Munjal added that their findings may have broader implications

Genes that control the production of hyaluronic acid in the semicircular canals of zebrafish are also present in the semicircular canals of mammals, suggesting that a similar process may be taking place

If this is the case, then studying the genes involved in the production of hyaluronic acid can help researchers understand the birth defects in the organs where hyaluronic acid promotes development

Munjal said: "This may be a broad, cross-species and cross-organ conserved mechanism
.
"

This mechanism can also be applied to bioengineering.
Researchers are trying to induce stem cells to form buds, tubes and other complex shapes.
The ultimate goal is to grow organs in the laboratory
.

Megason pointed out that the organ culture in the laboratory is still in progress, but the key step is to analyze how the organ is formed in the organism
.
Megason said: "We are trying to dissect the formation of complex organs (such as the inner ear) in the body, and then understand these processes quantitatively
.
We hope this will lay the foundation for cells to grow into any pattern and shape we want
.
"

Akankshi Munjal, Edouard Hannezo, Tony Y.
-C.
Tsai, Timothy J.
Mitchison, Sean G.
Megason.
Extracellular hyaluronate pressure shaped by cellular tethers drives tissue morphogenesis .
Cell , 2021; 184 (26): 6313 DOI: 10.
1016/j .
cell.
2021.
11.
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