Figure 3.

pRB loss disrupts sister chromatid cohesion. (A) Cells depleted of pRB (shRb) have an increased incidence of premature loss of sister chromatid cohesion (examples of separated sister are indicated by asterisks [*]). (B) Line scans through arms of sisters that maintain cohesion revealed an increase in interchromosomal distance in response to pRB loss. Each colored line represents a line scan through the arms of paired sister chromatids, with each chart depicting five line scans within a single representative cell. Prolonged mitotic arrest increased the interchromosomal distance (C) (error bars represent standard error [SEM]; P < 0.05 between control and sh-Rb cells at both 3 and 20 h) and promoted the complete loss of cohesion (D), as measured by the number of cells with one to three or four or more unpaired chromosomes.