STABILITY OF ISOLATED MITOTIC APPARATUS DURING STORAGE

Area of Science:

• Cell Biology
• Biophysics
• Developmental Biology

Background:

• The mitotic apparatus (MA) is crucial for cell division.
• Understanding the physical properties of the MA, such as birefringence, can provide insights into its structure and function.

Purpose of the Study:

• To compare the properties of mitotic apparatus (MA) isolated using different procedures.
• To investigate the factors influencing the birefringence and its stability in isolated MA.

Main Methods:

• Isolation of mitotic apparatus (MA) from sea urchin zygotes using hexylene glycol and glycerol-dimethylsulphoxide (MTME) methods.
• Measurement and comparison of MA birefringence under varying pH conditions and after extraction with H2O or 0.5 M KCl.
• Analysis of birefringence decay rates and stability over time.

Main Results:

• MA isolated with hexylene glycol exhibited pH-dependent birefringence, with lower pH increasing birefringence and stability.
• MA isolated with glycerol-dimethylsulphoxide (MTME) showed significantly greater birefringence stability, with decay rates approximately 1000 times slower than those isolated with hexylene glycol.
• Residual birefringence after extraction depended on isolation method, storage medium, and storage duration.

Conclusions:

• The isolation method significantly impacts the birefringence properties and stability of the mitotic apparatus (MA).
• Glycerol-dimethylsulphoxide (MTME) is a superior isolation medium for preserving MA birefringence stability.
• Multiple components, potentially including oriented ribosomes, may contribute to the birefringence of isolated MA.