Three-dimensional genome structures of single diploid human cells

Area of Science:

• Genomics
• Cell Biology
• Biophysics

Background:

• Three-dimensional genome structures are crucial for gene regulation and cellular functions.
• Characterizing these structures requires single-cell measurements, which has been challenging for diploid cells.

Purpose of the Study:

• To develop a novel method for high-resolution 3D genome structure reconstruction in single diploid human cells.
• To enable the study of genome architecture variations at the single-cell level.

Main Methods:

• Development of Dip-C (Diploid-cell Chromatin Conformation Capture), a single-cell method.
• Integration of META (Multiplex End-tagging Amplification) for whole-genome amplification and detection of chromatin contacts.
• Application of an imputation algorithm to link contacts to specific chromosome haplotypes.

Main Results:

• Successful reconstruction of 3D genome structures from single diploid human cells (lymphoblastoid and primary blood cells) with high spatial resolution.
• Localization of single-nucleotide and copy number variations within the nucleus.
• Observation of distinct structural differences between the two alleles of imprinted loci and the two X chromosomes.
• Identification of statistically significant differences in genome structures across different cell types.

Conclusions:

• Dip-C provides unprecedented insights into single-cell 3D genome organization in diploid organisms.
• Structural cell typing based on genome architecture is a valuable approach for understanding cell function and heterogeneity.
• The method opens new avenues for studying genome regulation and variation in health and disease.