Figure 2.
UV-C damage causes extended G2 arrest in PrimPol−/− cells leading to decreased cell death but increased aberrant mitotic division. (A) Cells were stained with DAPI and normal nuclei populations were compared for the percentage of fragmented nuclei 16 hrs after UV-C damage, n ≥ 3 independent experiments and error bars represent standard deviation. (B) Cells were also co-stained with α-tubulin to identify mitotic cells with multipolar spindles, example images (16 hrs after 2 J/m2 UV-C) (scale bar 10 µM). Quantification (16 hrs after 4 J/m2 UV-C) is shown in (C). (D) Cells were analyzed by FACS after propidium iodide staining at increasing recovery time-points after 4 J/m2 UV-C damage, average G2/M population is shown from 3 independent experiments. (E) Mitotic entry was analyzed by p-H3 staining during a 4 hr nocodozole treatment, 0 or 16 hrs after 0 or 4 J/m2 UV-C damage. (F) Cells unable to undergo replication during a 16 hr EdU labeling were counted after 0 or 4 J/m2 UV-C followed by a 24 hr recovery period, representative images shown in Figure S2C. In all cases error bars represent standard deviation and significance was measured using an unpaired students T-test (* p < 0.05, ** p < 0.01, ***p,0.001).