Figure 4. Hypothetic schematic representation of the mechanisms of chromothripsis induced by ionizing radiation.

(i) Chromothripsis occurs via micronuclei generated by ionizing radiation. When the entire cell is irradiated, for example, X-ray, the radiation damage induces formation of micronuclei. After chromothripsis occurs in the micronuclei, these micronuclei are then incorporated into a single chromatid. (ii) Chromothripsis may be directly induced by ionizing irradiation. When a portion of the nuclei is irradiated by microbeam (SPICE), multiple chromosomes sitting in the irradiated area are shattered into pieces, which are then rejoined via NHEJ.