Fig. 4. Cell cycle progression in L^tk- cells expressing WT and mutant MAP4 constructs. Cells grown on coverslips were fixed and expressing cells were quantified by scoring GFP-MAP4 fluorescence. Cells were scored for presence of: (1) two centrosomes with an intact nucleus (late G₂ or G₂/M transition); (2) mitotic spindle (M); or (3) midbody separating two daughter cells (early G₁), as illustrated in the schematic diagrams and fluorescence images. Cells expressing WT- and mutant MAP4 species (2 clones for each) were scored for the proportion of the total GFP-MAP4-expressing cells that were in late G₂, M, or early G₁ phase.