Scutoid Shape: A New Shape Discovered in Epithelial Cells

Did you think that you know all about different shapes? Well, there is circle, square, triangle, cylinder, pyramid, sphere, disc, cube, prism… and the list goes on. We know it all. But have you ever thought if there could be a shape that has never been discovered? Well, there at least was one! Scientists have discovered a brand new geomatric shape that we did not know about earlier. It’s called the Scutoid (pronounced as s-ku-to-id).

Scutoid shape was discovered by Gómez-Gálvez et al in 2018 in epithelial (skin) cells. The team published a paper titled Scutoids are a geometrical solution to three-dimensional packing of epithelia in the Nature magazine.

How does the Scutoid Shape Look Like?

A scutoid consists of a pentagonal and a hexagonal shape. Vertices of these two shapes are connected by curved connecting lines — but one of these connection is Y-shaped.

That’s the basic description of a scutoid. But as they say a picture speaks thousands of words, let’s take a look at scutoid. Following animation shows how two scutoids fit into each other:

Why Scutoid Shape is Important?

Most people will think that it is no new shape. In fact many will say that it is not a shape at all because a scutoid simply consist of many other shapes (like pentagon, hexagon, triangle, rectangle etc.).

But think about it. What constitutes a unique shape for us? Essentially it’s nature from where we get all our shapes. In nature we find all the shapes that we know about. Similarly, scutoid shape is also presented to us by nature. Scutoid is a unique, three-dimensional, complete shape in itself. It is neither a cylinder nor a polyhedron (prism).

As the title of the paper of Gómez-Gálvez et al suggests, scutoid is the shape in which nature packs skin cells. Epithelium is not just skin we see, these cells also make the outer lining of all our organs. Therefore, our body is in fact full of scutoid shaped cells.

The question is why nature opted to make a new shape? Why it could not make all the epithelial cells, says, cuboidal and pack them together like bricks in a wall? The answer to these questions is that the nature wants to be the most efficient. When a tissue grows, the epithelial cells need to change their shape. Nature wants to make this change with the least amount of energy. This is the reason why nature chose a new shape. Following image shows scutoid shape in soap bubbles.

Image courtesy: PhysicsWorld

Uses of Scutoid Shape

Now we know that scutoid is the shape that nature uses in packing epithelial cells. This information is very useful as we try to create artificial organs. Now we will be able to pack components in such organs in most energy-efficient manner.