Image-Based Modeling Reveals Dynamic Redistribution of DNA Damage into Nuclear Sub-Domains
Figure 8
Representative RIF Distribution Following Low-LET Radiation Exposure
DAPI is shown in blue, ATMp in green, and 53BP1 in red. (A) shows a representative 3-D image of a nucleus in orthogonal cross-section views. The same nucleus is seen in (B) as a 3-D surface rendering with only DAPI and ATMp RIF being segmented (i.e., blue and green surfaces, respectively; rendering done with Bitplane). This nucleus clearly shows the preferred location of ATMp RIFs at the interface between high and low DNA density regions. Different ATMp RIFs located at these interfaces are shown by colored arrows. (An arrow of the same color represents the same focus.) (C) and (D) overlay the identified locations of ATMp and 53BP1 RIFs (green disk and red circles, respectively) with the DAPI intensity and gradient images, respectively. Rdna and Rgrad values are given for each panel with colored text corresponding to the protein. One can see in (D) that the green RIFs shown by arrows are along high-gradient contours, which are reflected by a high Rgrad value. In contrast, the red RIF seem to locate themselves fairly randomly over the full nucleus, as reflected with Rdna and Rgrad values close to 1.