Diatoms divide through a distinct process shaped by their rigid cell walls, where cell division results in the two daughter cells being confined within the two halves of the parental cell wall.
Understanding Diatom Division
Unlike many other cells, diatoms possess a unique, hardened outer cell wall structure called a frustule. This frustule is composed of two overlapping halves, much like a petri dish. This structural constraint fundamentally dictates how diatoms undergo cell division.
The Division Process
Based on their rigid structure, the process of diatom division unfolds in specific stages:
- Cell division takes place inside the parental frustule.
- Due to the rigidity of the parental cell wall, the cell division results in the two daughter cells being confined within the two halves of the parental cell wall. The original wall essentially splits, with each daughter cell inheriting one half.
- Each daughter cell then produces a new half of a cell wall inside the old half it inherited.
- The daughter cells grow.
- Finally, they separate from their sister cell and the remnants of the parental wall.
This method means that one daughter cell receives the larger half of the original frustule and produces a new, smaller half, while the other daughter cell receives the smaller half and produces a new, even smaller half. This can lead to a gradual decrease in average cell size in some lineages over many generations, requiring specific mechanisms for size restoration.
