= Solution
\b[Both structures turn over rapidly, with visible <actin cables> disappearing faster than <actin patches> under these conditions.] Cable-positive <biological cells> fall from about 80% to essentially none within roughly two minutes. Polarized <actin patches> disappear over several minutes, while a transient depolarized-patch population persists before nearly all <actin patches> are lost by the end of the treatment time course.
Because ToxB binds <actin monomers> rather than existing <actin filaments>, a straightforward explanation is continuing normal disassembly without adequate replacement from assembly-competent <actin monomers>. The disappearance therefore reveals dynamic maintenance of structures that can look static in a fixed image. It does not show that the drug directly severs <actin cables>. Percentages of <biological cells> above a visibility threshold are not exponential decay curves for the lifetimes of individual <actin filaments>: cable thickness, staining sensitivity, <actin monomer> access and secondary loss of polarity can all affect the apparent timing. An analogous monomer-sequestering inhibitor established rapid <yeast> <actin turnover> in the classical study by <Kathryn R. Ayscough> and colleagues.<High rates of actin filament turnover in budding yeast and roles for actin in establishment and maintenance of cell polarity revealed using the actin inhibitor latrunculin-A by Kathryn R. Ayscough and others>[Actin-disassembly and recovery time courses]{ref}
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