Fig. 6: DNA damage checkpoint activation and telomere maintenance.

a Activation of the Rad50^wt/ho/lo-mediated DNA damage checkpoint, monitored by HU-induced Rad53 phosphorylation (α-Rad53). In contrast to untagged Rad50^wt/ho, the upshift of the phosphorylated Rad53 band is reduced in rad50\(\triangle\) and Rad50^lo-expressing cells (see also Supplementary Fig. 7b). α-Pgk1 controls equal loading. n = 2. b Representative telomeric PCR analysis for telomere 6Y′ in two clones per genotype. PCRs were performed with oligonucleotides oBL361 and oBL359 (see also “Methods” and Supplementary Fig. 7c). n = 4. c Quantification of telomeric PCR analysis of telomere 6Y′ in b. Fragment length was determined by using the 100 bp DNA ladder as size reference. n = 4 for each genotype; mean ± SD. Note that rad50\(\triangle\) and Rad50^lo-expressing cells have shorter telomeres than cells with Rad50^wt/ho.