Polarity and oriented cell division

The principle of new plant life is very similar to that of humans and animals: a single fertilized egg grows into a complex organism with millions of cells. Such a complex body plan can be created only if the rate and direction of cell division are strictly regulated. In plants, this control is very important, as plants do not contain mechanisms for cell migration or quick cell replacement like animals do: A rigid cell wall is formed soon after cell division, which fixes the new cell permanently.  Regulation of the direction of cell division is especially important in early embryos and stem cell niches (meristems), because these few cells lay the foundations for all future organs. Defects in the cell patterns of embryos and meristems can therefore be catastrophic for development.

To divide in the correct direction, cells have to know which way is up, down, left and right. Hypothetical proteins that localize robustly to one side of the cell yet are absent in others may provide this directional information. Recently a novel family of proteins has been identified in Arabdopsis thaliana that may fulfill this role. These proteins localize to specific parts of the cell and regulate cell division from there.

My project focuses on the exact function of these mysterious proteins, how they find their location and how similar proteins work in other plants. To answer these questions, I use a combination of genetics, cell biology, proteomics and microscopy techniques.