Figure 3

Schematic of subclonal assay to measure GCI rate. A single cell shows a well-defined pattern of gene cluster lengths ('Initial Pattern'--thick bands). Allowable, but currently unrepresented gene cluster lengths are shown as dotted lines. As mitotic division expands the clonal cell population in the absence of instability, gene cluster lengths are faithfully preserved ('No GCI'). Alternatively, instability generates sub-populations within the expanding population with altered cluster lengths giving rise to lower intensity 'minor bands' ('Low GCI'--thin bands indicated by arrows). High levels of instability generate a ladder-like pattern of minor banding with individual bands on the ladder differing by integer multiples of the unit repeat length ('High GCI'). Adapted from [18].