Figure 2

Heterogeneous motions of telomeres. Telomeres tracked using green fluorescent protein (GFP)-TRF1 are shown as representatives. GFP-TRF2 telomeric tracks are shown in A in Additional file 10. (A) Tracking of telomere motion by the software program Track4D, shown as end-to-end (E2E) distance in three-dimensional (3-D) space. An individual telomere has moved in space away from its 0 time-point position. Hence this displays motion of each telomere as a function of time T (seconds), and its distance (μm) from its starting point in the first timeframe. The effective diffusion coefficient, D, was calculated from these E2E measurements. (B) TrackIt4D tracking of telomere motion as demonstrated by plotting of the cumulative path distance traveled between time 0 and time T (seconds). (C) Tracking from kymographs (3-D tracks projected on to a xy plane) of a live UMUC3 cell showing one representative of a calm telomere and a jittering telomere. (D) Telomere motion statistics calculated from average E2E distance over sub-intervals. All distances traveled by the same telomere over time intervals of the same length were averaged together and plotted. Telomeres tracked for 200 seconds were plotted for intervals up to 100 seconds. (E) Telomere motion quantified as a histogram of D values, N = around 400 telomeres.