TAN1-mediated microtubule interactions may organize spindles and promote proper phragmoplast guidance. (A) WT maize epidermal cell expressing YFP-TUBULIN displays normal bipolar spindle morphology over time. (B)tan1 maize epidermal cell expressing YFP-TUBULIN has a disorganized spindle that recovers to canonical bipolar organization. Time lapse of spindles is shown in Video 2. (C and D) WT maize epidermal cells expressing CFP-TUBULIN (green) and TAN1-YFP (magenta). (C) Micrographs display both at the midplane and cortex of cell undergoing a longitudinal division. Phragmoplast and leading-edge microtubules at the cortex are positioned at the division site and are partially colocalized with TAN1. (D and E) Time lapse showing potential phragmoplast leading-edge microtubule contact and interaction with TAN1 at the division site (arrowheads). Fig. 4 D is shown in Video 3. (F and G) Time lapse and kymograph of TAN1-YFP at the division site. Scale bars, 10 µm.