A software solution for recording circadian oscillator features in time-lapse live cell microscopy

Area of Science:

• Cell Biology
• Biophysics
• Microscopy

Background:

• Mammalian circadian oscillators are studied using fluorescent and bioluminescent time-lapse microscopy.
• Existing tracking software struggles with cell movement and low reporter protein expression.
• Manual tracking or generic software are current, but limited, analysis methods.

Purpose of the Study:

• To develop improved methodology for time-lapse tracking of numerous moving cells.
• To create a software package for precise cell tracking and feature measurement.
• To enable nonbiased analysis of large fluorescent time-lapse microscopy datasets.

Main Methods:

• Developed a semi-automatic software package named Circadian Gene Express (CGE).
• CGE extracts cell trajectories by tracking displacements and delineating cell nucleus or whole cell.
• Analyzed single-cell circadian patterns and motility in NIH3T3 mouse fibroblasts.

Main Results:

• CGE enables fast and nonbiased analysis of large fluorescent time-lapse microscopy datasets.
• The software accurately tracks cell nucleus or whole cell, measuring reporter protein expression and displacement.
• Demonstrated application in analyzing circadian patterns and motility of NIH3T3 fibroblasts.

Conclusions:

• Circadian Gene Express (CGE) is a user-friendly, semi-automatic software for precise long-term tracking of moving cells.
• CGE accurately records cell parameters like reporter protein expression, velocity, and direction, even with low expression levels.
• The software is effective for widefield fluorescent and bioluminescence imaging, and adaptable for confocal microscopy.