The membrane-associated cytoskeleton in cultured lens cells. Electron microscopical visualization in cleaved whole-mount preparations and platinum replicas.

The membrane-bound cytoskeleton of bovine lens cells was investigated using different electron-microscopic methods. Cells were grown on glass coverslips and fixed in 0.5% glutaraldehyde, post-fixed and prepared for critical-point drying following standardized methods. Cells were broken open before post-fixation or after critical-point drying in order to expose the cortical cytoplasm. Cleaved, critical-point-dried cells were subsequently rotary replicated. Cells were also cleaved on grids before post-fixation. These cells were examined directly in the microscope. All methods showed the presence of a cytoskeletal network. Bundles and starlike foci of microfilaments and microtubules were usually found in close association with the membrane. Occasionally also intermediate filaments were observed, in a few cases running close to the microtubules. The reliability of the methods to visualize the membrane-bound cytoskeleton of lens cells is discussed.