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...

Disruption of the Actin Cytoskeleton with Cytochalasin D. U2OS human osteosarcoma cells were transduced with 'Cellular Lights' Actin-RFP (Actin-red fluorescent protein) and Cellular Lights MAP4-GFP (...

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...