Three dimensional fine structure of cultured cells: possible implications for subcellular motility

Area of Science:

• Cell Biology
• Cytoskeletal Dynamics
• Electron Microscopy

Background:

• Understanding the dynamic structural components of cells is crucial for elucidating cellular functions.
• Previous research has focused on well-defined structures like microtubules, but the broader cytoplasmic matrix remains less understood.

Purpose of the Study:

• To investigate the three-dimensional ultrastructure of whole motile cells.
• To identify novel cytoskeletal elements and their organization within the cytoplasmic matrix.
• To explore the potential role of these structures in subcellular movement.

Main Methods:

• Rat embryo cells were cultured and prepared using glutaraldehyde/osmium fixation.
• Cells underwent dehydration and critical point drying for transmission electron microscopy.
• Stereoscopic techniques were employed to reconstruct three-dimensional organelle arrangements.

Main Results:

• A filament-rich cytoplasmic matrix was observed with a widespread, fine-mesh network of interconnected filaments.
• This network closely surrounded all organelles and attached to the plasma membrane.
• Similar networks were visualized in unfixed cells using negative staining.

Conclusions:

• The identified filament network represents a significant component of the cell's structural organization.
• This network is proposed to be involved in force generation for various subcellular movements.
• Further research is warranted to fully characterize the composition and dynamics of this network.