Cell cycle dynamics of lamina-associated DNA

Area of Science:

• Cell Biology
• Genomics
• Epigenetics

Background:

• Mammalian interphase nuclei feature over a thousand lamina-associated domains (LADs) interacting with the nuclear lamina (NL).
• LADs play roles in gene regulation and chromosome folding, but their dynamic behavior during interphase, especially in G1 and S phases, remains largely uncharacterized.

Purpose of the Study:

• To investigate the dynamics of genome-nuclear lamina interactions during the mammalian cell cycle.
• To characterize the temporal establishment and dynamics of lamina-associated domains (LADs) at the nuclear lamina (NL).

Main Methods:

• Development of a novel antibody-based DamID technique (pA-DamID) for high-resolution mapping of genome-NL interactions.
• Utilizing cell synchronization and cell sorting in conjunction with pA-DamID to analyze LAD dynamics across the cell cycle.

Main Results:

• Lamina-associated domain (LAD)-nuclear lamina (NL) contacts are generally established rapidly early in the G1 phase.
• Distal LADs (~25 Mb) initially contact the NL and then detach, while centromere-proximal LADs gradually accumulate at the NL.
• Chromatin undergoing DNA replication (S-phase) exhibits transiently increased interactions with the nuclear lamina.

Conclusions:

• Genome-nuclear lamina interactions exhibit dynamic choreography throughout interphase progression.
• The pA-DamID technique provides a powerful tool for studying the dynamics of genome compartmentalization and nuclear organization.