SINGLE-CELL GENOMIC IMAGING TECHNIQUES FOR STUDYING CHROMOSOME TERRITORY ORGANIZATION DYNAMICS

Abstract

Background: The organization of chromosome territory (CT) is of fundamental importance for genome regulation, transcriptional control, DNA replication and chromatin stability. Traditional bulk-cell genomic studies often mask cell-to-cell variability and miss the dynamic spatial genome architecture within individual nuclei.
Objective: We have been developing advanced single-cell genomic imaging approaches to investigate the spatiotemporal dynamics of chromosome territory organization and its functional implications in nuclear architecture and gene regulation.

Methods: We used a variety of imaging methods including Fluorescence In Situ Hybridization (FISH), CRISPR-based live-cell genomic imaging, super-resolution microscopy, and multiplexed DNA imaging to visualize spatial chromosome arrangements at single-cell resolution. Quantitative image analysis was used to determine radial chromosome positioning, inter-territory interactions and temporal nuclear reorganization.

Results: Results showed significant spatial heterogeneity between individual cells, with ~35% variation in the chromosome radial positioning in different cell-cycle phases. Super-resolution imaging increased the localization precision to about 30 nm, and live-cell CRISPR imaging uncovered dynamic repositioning of chromosomes in response to transcriptional activation and chromatin remodeling. Multiplexed imaging also revealed increased frequencies of interchromosomal interactions under the cellular stress conditions.

Conclusion: Single-cell genomic imaging is crucial for deciphering chromosome territory dynamics, epigenetic regulation and disease-associated nuclear reorganisation with promising applications in cancer genomics, developmental biology and precision medicine.