Geometrical frustration of phase-separated domains in Coscinodiscus diatom frustules

Diatoms are single-celled organisms with a cell wall made of silica, called the frustule. Even though their elaborate patterns have fascinated scientists for years, little is known about the biological and physical mechanisms underlying their organization. In this work, we take a top-down approach and examine the micrometer-scale organization of diatoms from the Coscinodiscus family. We find two competing tendencies of organization, which appear to be controlled by distinct biological pathways. On one hand, micrometer-scale pores organize locally on a triangular lattice. On the other hand, lattice vectors tend to point globally toward a center of symmetry. This competition results in a frustrated triangular lattice, populated with geometrically necessary defects whose density increases near the center.

Automated summary

This study investigates the organization of diatoms and discovers two competing tendencies, possibly controlled by different biological pathways. One tendency is the local organization of triangular lattice pores, while the other tendency is the global pointing of lattice vectors towards a center of symmetry. This competition results in a frustrated triangular lattice with defects concentrated near the center.