Studies on microplasmodia of Physarum polycephalum. VII. Adhesion-dependent changes in the organization of the fibrillar actin system
Related Experiment Videos
1Institute of Cytology and Micromorphology, University of Bonn, Federal Republic of Germany.
Abstract:
Axenically-grown microplasmodia of the acellular slime mold Physarum polycephalum were used to study adhesion-dependent changes in the spatial organization of the cytoplasmic microfilament system. Results obtained by light- and electron microscopical techniques demonstrate the presence of a membrane-bound filament cortex in all microplasmodia, and the expression of additional cytoplasmic fibrils in specimens with tight contact to a substratum. The fibrils partly terminate in focal adhesion-sites and rather seem to serve a cytoskeletal than a contractile function.
Insights
Physarum polycephalum microplasmodia show adhesion-dependent changes in their microfilament system. New cytoplasmic fibrils form upon substratum contact, suggesting a cytoskeletal role rather than contraction.
Area of Science:
- Cell Biology
- Cytoskeletal Dynamics
- Slime Mold Research
Background:
- The acellular slime mold Physarum polycephalum is a model organism for studying cytoplasmic organization.
- Understanding the role of the microfilament system in cell adhesion is crucial for cell motility and tissue development.
Purpose of the Study:
- To investigate how adhesion to a substratum influences the spatial organization of the microfilament system in Physarum polycephalum.
- To characterize the nature and function of newly formed cytoplasmic structures in response to adhesion.
Main Methods:
- Axenic culture of Physarum polycephalum microplasmodia.
- Light and electron microscopy techniques for visualizing microfilament organization.
- Analysis of microfilament structures in relation to cell-substratum contact.
Main Results:
- All microplasmodia exhibited a membrane-bound filament cortex.
- Microplasmodia in tight contact with a substratum displayed additional cytoplasmic fibrils.
- These fibrils were observed to terminate at focal adhesion sites.
Conclusions:
- Adhesion to a substratum induces the formation of specific microfilament structures in Physarum polycephalum.
- These newly formed cytoplasmic fibrils appear to function primarily as a cytoskeletal support system.
- The findings suggest a role for these structures in mediating cell-substratum interactions beyond simple contraction.