ATAD5 knockdown retains inactive replication factories at the G2 phase. 72 h after transfection of ATAD5 or control siRNAs, HeLa cells were pulse-labeled with BrdU for 3 min, fixed, stained with anti-PCNA, anti-BrdU, and anti-cyclin B1 antibodies, and analyzed by confocal microscopy. (A) Representative images from ATAD5 knockdown cells. An asterisk indicates a cyclin B1–positive and BrdU-negative cell with PCNA foci. (B) The percentage of cells with PCNA foci in cyclin B1–positive and BrdU-negative cells (n = 110 for si-Ctrl cells; n = 97 for si-ATAD5 cells from a single experiment) was calculated. (C) Cells knocked down for ATAD5 were pulse-labeled with BrdU for 3 min, fixed, stained with anti-PCNA, anti-BrdU and the indicated antibodies, and analyzed by confocal microscopy. Bars, 5 µm.