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Joined 2026-09-21 Message
Incoming links: William J. Nicolas
William J. Nicolas 2026-11-05
William J. Nicolas has investigated cellular membrane architecture using three-dimensional electron microscopy. He is the first author of the 2017 study reconstructing plasmodesmata and comparing their structure with their capacity for intercellular transport.[ref]
A plasmodesma contains a strand of endoplasmic reticulum within its enclosing cell membrane. Electron tomography showed that newly formed channels after cytokinesis could have such close membrane contact that an open cytoplasmic sleeve was not visible. Later cell differentiation and expansion were associated with a changed arrangement. Yet the newly formed structures still permitted movement of macromolecules.[ref]
Architecture and permeability of post-cytokinesis plasmodesmata lacking cytoplasmic sleeves by William J. Nicolas and others. Abstract: developmental membrane remodeling and macromolecular diffusion
The result makes a useful scientific distinction: an image of an apparent opening and a measurement of plasmodesmal permeability are not interchangeable. Structural reconstruction describes the organization captured by the imaging method; a transport assay tests whether a defined molecule actually moves between cells. Combining these observations challenged a simple identification of a visibly open sleeve with all intercellular exchange.
Nicolas's contribution in this work connects spatially resolved membrane structure with a functional transport measurement, rather than treating plasmodesmata as featureless holes in a cell wall.
Homepage: www.wjnicolas.com/