Fig. 7

Microtubule dysfunctions associated with different doses of colcemid MT filaments are polymers of α- and β-tubulin subunits that assemble through dynamic processes. In non-polarized cells, filaments grow toward a positive end and form relatively linear filaments that extend outward from the cell centre toward the cell membrane. With low levels of colcemid ~ 20 nM, MT dynamics are suppressed, and filaments grow and shrink at a slower rate. Increased levels of colcemid ~ 65–80 nM produce more tubulin-colcemid complexes that distort normal tubulin-dimer subunit configurations, resulting in aberrant filament curvatures when these complexes become incorporated. Higher levels of colcemid > 100 nM result in short filaments (filament fragments), either due to curvature strains that result in breakage or the inability for filaments to form properly due to an excess of tubulin-colcemid complexes