TIRF time-lapse imaging of EB1-GFP (green) and mCherry-tubulin (red). EB1-GFP is seen on microtubule tips that grow to the cortex but does not accumulate on stable microtubule bundles at the equator, ...

Fluorescent micrograph of a Xenopus melanophore, showing microtubules (green), microtubule plus ends (red) and nucleus (blue). Honorable Mention, 2011 Olympus BioScapes Digital Imaging Competition®...

Microtubules in a Rac1(Q61L)-expressing PtK1 cell injected with Pak inhibitory fragment PBD/ID(H83L). Microtubules do not exhibit retrograde flow and undergo very little net growth. Epifluorescence i...

Microtubules in a control PtK1 cell at the edge of an epithelial cell island. Few pioneer microtubules rapidly grow into forming protrusions. The cell was microinjected with X-rhodamine-conjugated tub...

Microtubule fragments exhibiting net treadmilling in a Rac1(Q61L)-expressing PtK1 cell. Microtubule plus ends undergo dynamic instability while their minus ends depolymerize, resulting in net treadmil...

Human foreskin fibroblasts (HFF1) cells transfected with mKusabira-Orange EB3, a marker for growing microtubule ends. Note the dramatic movement of the bright fluorescent markers toward the cell peri...

Microtubules in a PtK1 cell injected with the Pak inhibitory fragment PBD/ID(H83L). Microtubules do not exhibit retrograde flow and undergo very little net growth. Epifluorescence image series were ac...

A normal X. laevis blastomere expressing three tandem GFPs fused to the ensconsin microtubule-binding domain (EMTB-3G; Faire et al., 1999). Single microtubules extend to the cortex, even in these larg...

Microtubules in a constitutively active Rac1(Q61L)-expressing PtK1 cell. Microtubules are subjected to continuous retrograde flow away from the cell edge, but many plus ends undergo net growth and rem...

Microtubules in a dominant-negative Rac1(T17N)-expressing PtK1 cell. Microtubules do not undergo retrograde flow, and microtubules rapidly switch between growth and shortening phases with little net c...