Quantifying Nuclear Shape Fluctuations During Early Mitosis

Area of Science:

• Cell Biology
• Biophysics
• Mechanobiology

Background:

• Nuclear shape dynamics are critical for cell division (mitotic progression).
• Understanding the biophysical properties of nuclear shape fluctuations can illuminate chromatin condensation and nuclear envelope breakdown.
• Existing methods lack detailed approaches for correlating nuclear mechanics with chromatin dynamics.

Purpose of the Study:

• To present a detailed methodology for monitoring nuclear shape fluctuations and their correlation with chromatin condensation.
• To provide a framework for analyzing the mechanical forces driving chromatin condensation and nuclear envelope instabilities.
• To offer a tool for exploring the mechanical coupling between chromatin and nuclear structure.

Main Methods:

• Live-cell imaging for high-resolution temporal tracking of nuclear shape changes.
• Computational analysis including segmentation and flickering spectroscopy.
• Pharmacological perturbations to manipulate chromatin condensation and cytoskeletal structures in synchronized HeLa cells.
• Extraction of biophysical parameters like nuclear effective tension and invaginations.

Main Results:

• Developed a robust workflow for correlating nuclear deformations with chromatin dynamics.
• Enabled quantitative analysis of nuclear shape fluctuations during the cell cycle.
• Provided a method to investigate the mechanical coupling between chromatin condensation and nuclear structure.

Conclusions:

• The presented methodology offers a powerful tool for studying nuclear mechanics and chromatin condensation.
• This approach is applicable to various conditions and crucial for understanding nuclear function.
• Insights gained are relevant for diseases characterized by nuclear abnormalities and disrupted cellular functions.