Dynamics of Rab11 endosomes in HD striatal cells declines and is enhanced upon expression of dominantly active Rab11. Time-lapse cell imaging of SThdhQ7/Q7 cells expressing XK-EGFP and mCherry-Rab11, SThdhQ111/Q111 expressing XK-EGFP and mCherry-Rab11, and SThdhQ111/Q111 expressing XK-EGFP and mCherry-dArab11. Prior to imaging and during the whole period of imaging, cells were treated with β-cycloheximide to ascertain the detection of XK-EGFP in the endocytic pathway. A series of six consecutive frames were chosen from Videos 1, 3, and 5, respectively, to highlight cotrafficking of XK-EGFP with mCherry-Rab11 or with mCherry-dArab11 in motile vesicles and the dynamics of large tubulovesicular structures labeled with XK-EGFP and mCherry-Rab11 or with XK-EGFP and mCherry-dArab11. Boxed regions were enlarged and shown below the corresponding frame. Arrows in insets trace motile structures containing both XK-EGFP and mCherry-Rab11/dArab11, whereas arrowheads point to structures changing in their size. Dashed circles indicate motile structures containing both XK-EGFP and mCherry-Rab11/dArab11 disappearing in the following images, and dashed polygons identify those appearing in the following images. Enlarged dashed contours indicate dynamic changes in the morphology of large vesiculotubular structures, likely reflecting events of vesicle fusion and budding. Scale bars in the last frame of each of SThdhQ7/Q7, SThdhQ111/Q111, and SThdhQ111/Q111 + dArab11: 10 μm (upper), 2 μm (middle), and 0.5 μm (lower). Source data are available for this figure: SourceData F3.