P.C. Rossin College of
Engineering and Applied Science
Study reveals a new geometric shape used by nature to pack cells efficiently

As an embryo develops, tissues bend into complex three-dimensional shapes that lead to organs. Epithelial cells are the building blocks of this process, forming, for example, the outer layer of skin. They also line the blood vessels and organs of all animals.

These cells pack together tightly. To accommodate the curving that occurs during embryonic development, it has been assumed that epithelial cells adopt either columnar or bottle-like shapes.

However, a group of scientists dug deeper into this phenomenon and discovered a new geometric shape in the process.

They uncovered that, during tissue bending, epithelial cells adopt a previously undescribed shape that enables the cells to minimize energy use and maximize packing stability. The team’s results have been published in Nature Communications in a paper called “Scutoids are a geometrical solution to three-dimensional packing of epithelia” (DOI: 10.1038/s41467-018-05376-1).

The study is the result of a United States-European Union collaboration between the teams of Luis M. Escudero (Seville University, Spain) and that of Javier Buceta, associate professor of bioengineering and a faculty member in the chemical and biomolecular engineering department at Lehigh. Pedro Gómez-Gálvez  and Pablo Vicente-Munuera are the first authors of this work, which also includes scientists from the Andalucian Center of Developmental Biology and the Severo Ochoa Center of Molecular Biology, among others.

Buceta and his colleagues first made the discovery through computational modeling that utilized Voronoi diagramming, a tool used in a number of fields to understand geometrical organization.

“During the modeling process, the results we saw were weird,” says Buceta. “Our model predicted that as the curvature of the tissue increases, columns and bottle-shapes were not the only shapes that cells may developed. To our surprise, the additional shape didn’t even have a name in math! One does not normally have the opportunity to name a new shape.”

The group has named the new shape the “scutoid,” for its resemblance to the scutellum—the posterior part of an insect thorax or midsection.

Read the full story in the Lehigh University News Center.

Javier Buceta

Javier Buceta, associate professor of bioengineering and also of chemical and biomolecular engineering

Scutoid

Researchers have discovered the scutoid, a geometric shape adopted by epithelial cells that enables the cells to minimize energy use and maximize packing stability during tissue bending. Image credit: University of Seville