An Electron Tomography Microscope for Analysis of Biomaterials at Nanoscale
02 / 2006 - 12 / 2012
Localization and spatial organization of gene products over time determine cell function, and knowledge about them is paramount to biotechnological applications. The Electron Tomography Microscope (ETM) reaches a resolution allowing analysis of molecular cell architecture in 3D at nm scale. To extend the Electron Microscopy tools (SEM and TEM) of Wageningen University for linking genomics to molecular architecture of cells and (bio)nanotechnological research, we request funding for an ETM. Although the equipment will be available to the whole scientific community of Wageningen-UR and the Research School of Experimental Plant Sciences which combines PhD level education of the universities of Wageningen, Utrecht, Nijmegen, Leiden and Amsterdam, and to external users, in this proposal we focus on the planned projects of the research groups Plant Cell Biology (PCB) and Virology (VIR), that have combined their EM equipment in the Electron Microscopy Centre Wageningen (EMCW) and will manage the new ETM.
PCB research focuses on the role of cytoskeletal and cellulose polymers in cell elongation, -division, and -wall formation. A systems biology approach is chosen, in which quantitative laboratory experiments are combined with theoretical modeling, an approach first used in the study of cellulose texture formation of the cell wall. The studies in which the ETM is needed involve investigation of fabrication and routing of the cellulose synthase complex through the endomembrane system of endoplasmatic reticulum, Golgi apparatus and endosomal compartment, the role of the cytoskeleton in determination of the location of insertion of this complex into the plasma membrane, possibly by exocytosis, the nanostructure of this complex, the organization of the wall polymers produced around cells and from isolated synthases in vitro, and the nanostructure of single cellulose microfibrils.
Research at the Laboratory of Virology focuses on a selected number of important model viruses of plants (Tomato spotted wilt virus (TSWV) and Cowpea mosaic virus (CPMV) and arthropods (insects: Baculoviruses; Crustacean: White spot syndrome virus (WSSV)). Research includes unravelling molecular mechanisms of the viral infection cycle (viral gene expression, genome replication and transcription), host resistance, RNA interference and the use of viruses as gene vectors, but a very important aspect of the research program concerns the mechanism of viral spread from cell to cell and within the host organism. Electron microscopy has proven to be indispensable to relate our advanced knowledge of the function of viral genomes/proteomes to essential host factors that support processes in the viral infection cycle. ETM is particularly requested for our research on the mechanisms of virus attachment and entry into the cell, virus morphogenesis (involving the endomembrane system) and nanotubule-guided transport of virions through plasmodesmata.