Fig. 1
eGFP-Htt-Q74 aggregate formation upon doxycycline induction. PC12 cells expressing eGFP-Htt-Q74 HD upon doxycycline induction were imaged at various time points post-induction (4 – 120 h) using fluorescence living cell imaging. Image analysis was performed using a modified version of the Argos system, an interactive setup to combine numerical analysis with visual analysis (a-p, representative examples of at least four replicates per time point). a-d and i-l show the Htt-Q74 eGFP expressing cells at the various post-induction time points. Cell outlines (red) at different time points were detected by image analysis. e-h and m-p show the intracellular eGFP-Htt-Q74 aggregates (green) detected in each image at the different time points. Red arrows in c and g point to the aggregates at time point 24 h post-induction. Aggregate formation was first observed in cells around 24 h post-induction. Cell and aggregate volumes were calculated in at least four images at each time point (24–120 h after doxycycline induction). Aggregates detected in cells were binned based on their loge(volume). The number of aggregates per cell volume was determined for each bin and plotted separately for the intermediate (24-48 h, panel q) and late (72-120 h, panel r) time points