Fig. 4.

FISH analysis of FHIT/FRA3B deletions. Frequency (%) of gaps and breaks at FRA3B in hybrid clones after 24-h APH treatment; n = 100 sites examined. Frequency of fragile-site breakage is presented as the percentage of chromosome 3s with breaks at FRA3B. Data were normalized with respect to total chromosome gaps and breaks to eliminate variability in cellular response to APH from clone to clone. All error bars indicate the 95% confidence interval. Locations of deletions in hybrid clones with respect to FHIT exons are shown as horizontal gray bars in the map. Clones are listed from smallest to largest deletion size. *, Numbers of FRA3B breaks in hybrid clones with deletions are significantly different from control hybrid cell lines (P = 0.006, 0.014, 0.002, 0.05, 0.002, 0.014, and 0.001 for clones 6-3, 3-16, p-10, p-154, 3-5, and p-43, respectively.