Coarse-grained chromatin dynamics by tracking multiple similarly labeled gene loci

Area of Science:

• Cellular biology
• Genomics
• Biophysics

Background:

• Tracking chromatin configuration in live cells is a major challenge.
• Current methods using distinguishable fluorescent labels limit the number of observable loci.

Purpose of the Study:

• To theoretically analyze how single-particle tracking of identically labeled loci can determine locus identity.
• To investigate the feasibility of inferring temporal dynamics of chromatin configuration in living cells.

Main Methods:

• Simulations of Rouse model polymers.
• Theoretical analysis of single-particle tracking data.
• Modeling of identically and alternately labeled loci.

Main Results:

• Probability of correct locus assignment converges exponentially with increased observations.
• Convergence rate is weakly dependent on the number of labeled loci.
• Alternately labeled loci show faster convergence than identically labeled ones.
• Dynamic loop models also show exponential convergence.

Conclusions:

• Single-particle tracking of multiple labeled loci is a feasible method for inferring chromatin dynamics.
• This approach allows for high-fidelity identification of genomic positions over time.
• The method is applicable to various chromatin polymer models, including those with dynamic loops.