Figure 5. Cells deficient for β2SP show defective S-phase specific chromosome repair.

Cell cycle phase specific chromosomal aberrations induced by IR in human cells. A., B. Metaphases of human cells showing centromeres green and telomeres red detected by FISH as described previously [19, 20, 63]. Metaphase chromosomes from control A. and G1-type metaphase chromosomes, arrows indicate dicentrics B.. C.,D. S- and G2-type chromosome aberrations detected by Giemsa staining as described previously [64, 65], S-phase C. showing radials indicated by black arrow C. and G2-phase D. showing breaks and gaps indicated by red arrows. E.-G. Quantification of chromosomal aberrations: G1-phase type E., S-phase type F. and G2-phase type G.. **p < 0.01, Student t-test.