Analysis of the mobility of DNA double-strand break-containing chromosome domains in living mammalian cells.

DNA double-strand breaks (DSBs) are among the most dangerous types of DNA damage. Unrepaired, DSBs may lead to cell death, and when misrejoined, they can result in potentially carcinogenic chromosome rearrangements. The induction of DSBs and their repair take place in a chromatin microenvironment.

Induction of linear tracks of DNA double-strand breaks by alpha-particle irradiation of cells.

Understanding how cells maintain genome integrity when challenged with DNA double-strand breaks (DSBs) is of major importance, particularly since the discovery of multiple links of DSBs with genome instability and cancer-predisposition disorders. Ionizing radiation is the agent of choice to produce DSBs in cells; however, targeting DSBs and monitoring changes in their position over time can be difficult. Here we describe a procedure for induction of easily recognizable linear arrays of DSBs in nuclei of adherent eukaryotic cells by exposing the cells to alpha particles from a small Americium source (Box 1).

Dynamics of DNA double-strand breaks revealed by clustering of damaged chromosome domains.

Interactions between ends from different DNA double-strand breaks (DSBs) can produce tumorigenic chromosome translocations. Two theories for the juxta-position of DSBs in translocations, the static "contact-first" and the dynamic "breakage-first" theory, differ fundamentally in their requirement for DSB mobility. To determine whether or not DSB-containing chromosome domains are mobile and can interact, we introduced linear tracks of DSBs in nuclei.