Wavelet transform analysis of chromatin texture changes during heat shock.

Area of Science:

• Cell Biology
• Biophysics
• Image Analysis

Background:

• Chromatin organization is crucial for cellular function.
• Heat shock induces rapid changes in cellular structures.
• Quantifying these dynamic changes requires sensitive analytical tools.

Purpose of the Study:

• To apply 'à trou' wavelet texture analysis for quantifying chromatin organization.
• To investigate heat-induced changes in chromatin texture in living cells.
• To correlate chromatin textural dynamics with heat shock factor 1 (HSF1) localization to nuclear stress bodies (nSBs).

Main Methods:

• Utilized 'à trou' wavelet transform for multiscale texture analysis.
• Quantified chromatin texture using statistical orders (mean, standard deviation, skewness, kurtosis) of wavelet coefficients.
• Employed laser scanning and spinning disk confocal microscopy to observe living cells.
• Analyzed changes during heat shock (15 min, 30 min, 1 h) and subsequent recovery.

Main Results:

• 'À trou' wavelet analysis demonstrated sensitivity to heat-induced chromatin texture changes.
• Significant alterations were observed even after short heat shock durations, particularly affecting skewness and standard deviation.
• Progressive changes correlated with heat shock duration, revealing fine, pixel-wise alterations.
• Chromatin textural dynamics were compared with the formation of nuclear stress bodies.

Conclusions:

• 'À trou' wavelet texture analysis is a sensitive and efficient tool for investigating subtle chromatin changes.
• The method can detect early and progressive alterations in chromatin organization due to stress.
• This approach offers valuable insights into cellular responses to environmental stimuli.