Single-molecule DNA visualization using AT-specific red and non-specific green DNA-binding fluorescent proteins.

Area of Science:

• Genomics
• Molecular Biology
• Biophysics

Background:

• Single-cell genome analysis offers insights but faces technical challenges due to DNA amplification.
• Current methods require DNA amplification, which can introduce biases and errors.

Purpose of the Study:

• To develop a novel method for direct visualization of genomic maps on large DNA molecules.
• To enable sequence-specific optical identification of single DNA molecules without amplification.

Main Methods:

• Constructed fluorescent protein-fused DNA-binding proteins (H-NS, BRCA1, HMG, KW repeat motif).
• Utilized a combination of A/T specific binders (H-NS-mCherry, HMG-mCherry) and non-specific binders (BRCA1-eGFP, 2(KW)2-eGFP repeat).
• Developed a two-color DNA physical mapping strategy using red and green fluorescent proteins.

Main Results:

• Successfully visualized genomic maps on large DNA molecules directly, without amplification.
• Achieved sequence-specific two-color DNA physical mapping.
• Demonstrated efficient optical identification of single DNA molecules.

Conclusions:

• The novel approach provides a powerful tool for direct genomic visualization.
• This method overcomes limitations of DNA amplification in single-cell genome analysis.
• Enables precise optical identification of single DNA molecules for advanced biological studies.