Figure 2.

DSB dynamics as a function of the DSB position and NCS concentration. (A) DSBs are detected and tracked in 53BP1-mCherry signal (yellow markers). The trackable DSBs are divided into the periphery DSBs (less than 1 μm from the nuclear envelope, yellow crosses) and interior DSBs (yellow circles), and untrackable DSBs are marked by yellow dots (see Materials and Methods). (B) An enlargement of the boxed-in areas in (A) is given, showing examples of the interior and periphery DSB trajectories and their area A_L given by a convex hull (yellow solid line). DSB trajectories are color-coded by their temporal evolution (blue to red). (C) Mean-square displacement (MSD) for trajectories of the periphery DSBs (crosses) and interior DSBs (circles) from (B) and a fit to MSD(τ) = C + Bτ^α are shown (purple line). (D) Distributions of the area explored at short timescales A_s, the exponents α, and area explored at long timescales A_L obtained from individual DSB trajectories for populations of the interior and periphery DSBs are shown. Numbers in the x axis label indicate the number of DSBs analyzed. Dot, solid line, and dashed line in the violin plots correspond to the mean, median, and quartiles, respectively. (E) Average MSD for all trajectories for interior and periphery DSBs in a given experiment is shown. MSD measured for cells fixed in formaldehyde (black line, N_DSB = 152, N_Cells = 42) defines the noise floor of our experiment. Error bars are shown in Fig. S1. (F) Distributions of the DSB density ρ_B are shown; numbers in legend indicate the number of nuclei analyzed. Scale bars, (A) 3 μm, (B) 100 nm. To see this figure in color, go online.