Spatial structures in microtubular solutions requiring a sustained energy source.

Area of Science:

• Cell Biology
• Biophysics
• Biochemistry

Background:

• Microtubules organize cellular interiors and are crucial for cell division, morphogenesis, and embryo development.
• Cellular responses to stimuli often involve dynamic changes in microtubule spatial organization.

Purpose of the Study:

• To investigate the spontaneous formation of macroscopic patterns in microtubule solutions.
• To elucidate the physical and chemical mechanisms underlying microtubule self-organization.
• To explore the potential role of microtubules in forming energy-dissipative structures.

Main Methods:

• Observation of spontaneous stripe formation in microtubule solutions.
• Small-angle neutron scattering to analyze microtubule alignment within stripes.
• Phosphorus Nuclear Magnetic Resonance (NMR) spectroscopy to track phosphate conversion.

Main Results:

• Microtubule solutions spontaneously formed alternating white and dark stripes (1 mm wide, 1 cm long).
• Small-angle neutron scattering revealed oblique microtubule alignment within stripes, with orthogonal orientations between adjacent stripes.
• Energy-liberating conversion of organic to inorganic phosphate was observed, indicating an energy-dissipative process.

Conclusions:

• The observed striped structures are energy-dissipative, analogous to chemical dissipative structures like the Belousov-Zhabotinski reaction.
• Microtubules are capable of forming dissipative structures, suggesting a fundamental role in biological organization.
• These microtubular dissipative structures may be relevant to processes such as mitosis and embryonic morphogenesis.