A comprehensive view of somatic mosaicism by single-cell DNA analysis

Area of Science:

• Genomics
• Molecular Biology
• Human Genetics

Background:

• Single-cell DNA sequencing is crucial for studying somatic mosaicism.
• Analysis must address DNA amplification artifacts.
• Understanding cellular mutation accumulation is key.

Purpose of the Study:

• To develop and validate a comprehensive single-cell genomics approach.
• To analyze mutation burdens and spectra in human tissues.
• To reconstruct cellular ancestries and identify mutation origins.

Main Methods:

• Primary template-directed amplification (PTA) and sequencing of 102 single nuclei.
• Validation using duplex sequencing.
• Analysis of chromosomal abnormalities and rearrangements.

Main Results:

• Heterogeneous mutation burdens and spectra observed across cells and organs.
• Identified signatures of APOBEC activity and tobacco exposure.
• Detected chromosomal aneuploidies, Y chromosome loss, and T-cell receptor rearrangements.
• Reconstructed cellular ancestries from embryonic mutations.

Conclusions:

• The developed single-cell genomics approach provides an expansive view of somatic mutations.
• This method reveals insights into development, aging, and tissue-specific mutation processes.
• Findings offer a more complete understanding of somatic mosaicism than bulk sequencing.