Homblé Fabrice, Léonetti Marc
Structure et Fonction des Membranes Biologiques, Centre de Biologie Structurale et de Bioinformatique, Université Libre de Bruxelles, Campus Plaine, Bruxelles, Belgique.
Trends Plant Sci. 2007 Jun;12(6):253-9. doi: 10.1016/j.tplants.2007.04.007. Epub 2007 May 10.
Fucoid zygotes are model cells for the study of symmetry breaking in plants. After fertilization, their initial spherical symmetry reduces to an axial symmetry, even in the absence of any external cue. This indicates that zygotes have an intrinsic ability to break symmetry in a way that is solely dependent on their internal biochemical and/or biophysical state. In our opinion, symmetry breaking is a self-organized process. It arises around the fucoid zygotes from the ion dynamics through channels (voltage-dependent calcium channels and a potassium leak) and outside the membrane (electrodiffusion owing to slower calcium diffusion compared with potassium). The robustness of this self-organized process and its lability ensure its relevance in plants where symmetry breaking is correlated with transcellular ion currents.
