6578 Nucleic Acids Research, 2011, Vol. 39, No. 15 Figure 5. lacO-LacI induces UFB formation. (A) Examples of UFBs in wild-type cells with the lacO array after 24 h of LacI (++) induction. (B) Quantiﬁcation of the percentage of dividing cells with UFBs in wild-type and mutant strains with and without the lacO array after 24 h of LacI (++) induction. Mean values are from at least three independent experiments with 100 binucleate cells scored in each experiment. Error bars are the standard deviations. (C) Example showing localization of Histone H3.2-GFP to a UFB. (D, top panel) Example of cell with a UFB in which a division septum (indicated by the arrowhead) is in the process of forming. (D, bottom panel) Example of a cell in which a division septum has formed and appeared to have broken a UFB. (E) The distribution of cell lengths in asynchronously growing populations of wild-type and chk1D strains with and without the lacO array after 24 h of LacI (++) induction (n 300). (F) Ade+ recombinant frequencies (top panel) and percentage of Ade+ recombinants that are conversion-types (bottom panel) in lacO array-containing strains expressing LacI (+). Error bars are the standard deviations about the mean.