Diatom systematics and wall ontogeny

Systematics of naviculoid diatoms and diatom wall ontogeny

Diatoms are unique in having bipartite siliceous cell walls. These are formed within a membrane-bound vesicle before release to the cell exterior.

For almost 200 years diatom systematics has been largely based on wall symmetry and pattern, but we still understand little of the process by which walls are produced, or the factors that can modify them.

Key aims of this research:

  • To understand diatom wall ontogeny in raphid diatoms, determining the intrinsic and extrinsic factors that can modify structure and morphology.
  • To incorporate this information into our choice and interpretation of wall characters for diatom systematics, particularly for naviculoid diatoms.

The research also seeks to:

Pinnularia species of diatom

Pinnularia species of diatom

  • Integrate phenotypic variability into the process of species definition and identification. It does this by combining microscopical and experimental techniques, using clonal cultures to track morphogenesis and investigate the effects of changing environment on structure.
  • Investigate cellular processes that control polarity setting and the development of different symmetry arrangements.
  • Address questions relating to the evolution of particular structures or symmetries by studying different families and orders of diatoms.
  • Produce a revised classification of the naviculoid diatoms – this is the ultimate systematic aim.
Botany staff involved in this project:

E J Cox