March 1, 2024

More mysteries in embryology than once thought

As an example of how much scientists still have to learn about developmental biology, US researchers are investigating a largely unknown third group of cells which can form all major types of human tissue. “VENT cells are a unique category of multi-potent cells,” says Dr Douglas P. Dickinson, of the Medical College of Georgia. In an article in the Journal of Anatomy he reviews the 10-year history of VENT cell research. It appears that these rare cells escape from the bottom of the neural tube early in development after the tube closes to form the brain.

Although the very existence of VENT cells is questioned by some scientists, the MCG researchers believe that this is no longer a matter for debate. But VENT cells do challenge long-held notions of what type of cells form what type of tissue. Apparently they somehow contribute to the development of the four basic tissue types. If they are removed, defects in the heat, gut, skull and other areas result. The VENT cells may also work like a centralised source which supplies stem cells for all tissues. “VENT cells would be a simple way of providing stem cells to various tissues because nerves connect to every tissue and you would not be dependent on every muscle, every nerve, every bone to make sure you keep a small reserve,” says Dr Paul Sohal, another researcher at the College.

And in another development, scientists at Johns Hopkins University have found that the shape of cells may be at least as influential as signal molecules in directing the development of tissues. Earlier research had focused on the role of signal molecules, but this latest study appears to show that cell shape has a crucial effect upon early developmental fate.