Figure 4: Stable bundle formation at the leading edge of the phragmoplast.
From: Mechanism of microtubule array expansion in the cytokinetic phragmoplast
(a) Microtubule behaviour on the leading edge of the phragmoplast in a cell expressing GFP-α-tubulin. The boxed region in the left panel is shown enlarged in the right panels. Drawing under each panel indicates microtubule distribution, and coloured microtubules highlight microtubules of interest. The white arrow indicates interdigitated microtubules in the midzone. Arrowheads indicate microtubules becoming bundled. In the left panel scale bar, 5 μm. (b) Summary of microtubule behaviour at the leading edge of the phragmoplast. (c) An EB1-GFP expressing cell fixed and stained with anti-α-tubulin. Maximum-projection image of 30 optical slices with 0.25 μm intervals. Arrowheads show EB1 comets around the leading edge of the phragmoplast. In the right panel scale bar, 5 μm. (d) Localization of tRFP-α-tubulin and GFP-MAP65-1a in the phragmoplast. Boxed region of the merged picture (left panel) is enlarged and shown in right panels. Large arrows indicate oblique dynamic microtubules, and small arrows indicate outermost bundles of stable microtubules. Note that the oblique microtubules are highlighted as green and the outermost bundle is highlighted as magenta in the merged panel, showing the weak GFP-MAP65-1a signal on the oblique microtubules and the strong signal on the outermost bundle. Scale bar, 5 μm. (e) GFP-MAP65-1a behavior on the leading edge of the phragmoplast. Arrows show accumulation of GFP-MAP65-1a in the leading edge. In the bottom-right panel scale bar, 5 μm.
