Radiation exposure induces massive apoptosis and G2/M arrest in NSPC.

<p><b>A</b> Number of PAX6(+)TBR2(−) (top), PAX6(+)TBR2(+) (middle) and PAX6(−)TBR2(+) (bottom) nuclei per bin 4 h after a 1 Gy (orange) or 0 Gy (green, control) radiation exposure. Mean values ± SEM were calculated from <i>WT</i> (closed squares) and <i>Rad54−/−</i> (open squares) embryos from at least three distinct litters for each genotype. Stars correspond to statistical analysis between <i>WT</i> and <i>Rad54−/−</i> curve. <b>B</b> Ratio between total PAX6(+)TBR2(−) (left), PAX6(+)TBR2(+) (middle) and PAX6(−)TBR2(+) (right) nuclei and unirradiated control, expressed as percentage. Mean values ± SEM were calculated from <i>WT</i> (black) and <i>Rad54−/−</i> (white) embryos from at least three distinct litters for each genotype.</p

<i>Rad54</i> disruption delays mitotic cells reappearance after radiation exposure.

<p>Ratio between pH3(+) nuclei after irradiation and unirradiated control, expressed as percentage Mean values ± SEM were calculated from <i>WT</i> (black) and <i>Rad54−/−</i> (white) embryos from at least three distinct litters for each genotype. Stars above the histograms correspond to statistical comparison with unirradiated controls. Stars above lines correspond to statistical analysis between <i>WT</i> and <i>Rad54−/−</i> genotypes.</p

No interference of <i>Rad54</i> disruption with radiation response of G1 and postmitotic cells within 8 hPI.

<p><b>A</b> Scheme of the experimental design. <b>B and C</b> Number per bin of normally shaped (left) and pyknotic nuclei (right), from top to bottom, EdU(−)BrdU(+) (<b>B</b>) and EdU(−)BrdU(−) (<b>C</b>) nuclei 4 h (top) and 8 h (bottom) after a 1 Gy (orange), 2 Gy (black) or 0 Gy (green, control) radiation exposure. Mean values ± SEM were calculated from <i>WT</i> (closed squares) and <i>Rad54−/−</i> (open squares) embryos from at least three distinct litters for each genotype. Stars correspond to statistical analysis between <i>WT</i> and <i>Rad54−/−</i> curves.</p

<i>Rad54</i> disruption lengthens G2/M arrest and delayed S-phase progression in S and G2 irradiated NSPC.

<p><b>A</b> Scheme of the experimental design. Repeated BrdU injections were performed in order to insure perfect staining of all neural cells newly entering S phase during the 4 or 8 hours PI. <b>B and C</b> Number per bin of normally shaped (left) and pyknotic nuclei (right), from top to bottom, EdU(+)BrdU(−) (<b>B</b>) and EdU(+)BrdU(+) (<b>C</b>) nuclei 4 h (top) and 8 h (bottom) after a 1 Gy (orange), 2 Gy (black) or 0 Gy (green, control) radiation exposure. Mean values ± SEM were calculated from <i>WT</i> (closed squares) and <i>Rad54−/−</i> (open squares) embryos from at least three distinct litters for each genotype. Stars correspond to statistical analysis between <i>WT</i> and <i>Rad54−/−</i> curves.</p

Disruption of <i>Rad54</i> has no effect on mouse cortical development.

<p><b>A</b> Coronal section of the cerebral hemisphere of E14.5 (left) and E15.5 (right) <i>WT</i> (top) and <i>Rad54−/−</i> (bottom) embryos immunostained with PAX6 (green) and TBR2 (red). Ventricles are on the left of each section. Scale bars, 10 µm. <b>B</b> Number of PAX6(+)TBR2(−) (top), PAX6(+)TBR2(+) (middle) and PAX6(−)TBR2(+) (bottom) nuclei per bin at E14.5 (left) and E15.5 (right). Mean values ± SEM were calculated from <i>WT</i> (black squares) and <i>Rad54−/−</i> (open squares) embryos from at least three distinct litters for each genotype. <b>C</b> Top: scheme of experimental design. Bottom: Number of BrdU(+) nuclei per bin at E14.5, 1 h following a single injection of BrdU. Mean values ± SEM were calculated from <i>WT</i> (black squares) and <i>Rad54−/−</i> (open squares) embryos from at least three distinct litters for each genotype. <b>D</b> Top: Ventricle margins of hemispheres of E14.5 <i>WT</i> (left) and <i>Rad54−/−</i>(right) embryos stained by dapi (blue) and immunostained for pH3 (red). Scale bars, 10 µm. Bottom: Number of pH3(+) nuclei/100 µm of ventricular margin at E14.5. Mean values ± SEM were calculated from <i>WT</i> (black) and <i>Rad54−/−</i> (white) embryos from at least three distinct litters for each genotype.</p