Fluorescent indicators for simultaneous reporting of all four cell cycle phases

Area of Science:

• Cell Biology
• Molecular Biology
• Biotechnology

Background:

• Simultaneous visualization of all four cell cycle phases in living cells is a significant challenge in cell biology.
• Existing methods may lack the resolution or orthogonality needed for comprehensive cell cycle tracking.

Purpose of the Study:

• To develop a robust method for simultaneous visualization of all four cell cycle phases in living cells.
• To engineer new fluorescent reporters for specific cell cycle transitions and mitotic events.

Main Methods:

• Development of an intensiometric reporter for the S to G2 phase transition.
• Engineering of a far-red fluorescent protein, mMaroon1, for visualizing chromatin condensation during mitosis.
• Integration of these novel reporters with the existing Fucci system to create a comprehensive four-color indicator set.

Main Results:

• Successful creation of Fucci4, a set of four orthogonal fluorescent indicators.
• Demonstration of simultaneous visualization of all cell cycle phases (G1, S, G2, M) in living cells.
• mMaroon1 effectively visualizes chromatin condensation in mitosis, complementing other reporters.

Conclusions:

• Fucci4 provides a powerful tool for real-time, multi-phase cell cycle analysis in living cells.
• This system enhances the ability to study cell cycle dynamics and perturbations.
• The developed reporters offer improved resolution and orthogonality for cell cycle research.