Stabilization of the metaphase spindle by Cdc14 is required for recombinational DNA repair (2016)
Figure 4

Figure 4. Cdc14 stimulates DSBs recruitment to the SPBs in response to DNA damage.

A) Diagram showing the genomic background and the approximation used to measure DSB-SPB interaction. Cnm67-RFP and Ddc2-GFP were used as SPB and DSB markers respectively. D1: inter-SPB distance; D2: DSB distance to proximal SPB; D3: DSB distance to distal SPB. Graph represents the mean ± SD of D1, D2 and D3 distances from three independent experiments. At least 100 cells per experiment were scored using the maximum projection of three z-planes. P values were calculated using a 2-tailed unpaired Student t test. A representative picture of a wild-type strain depicting DSB-SPB interaction is shown. Scale bar: 3μm.

B) Time-lapse experiments in living cells showing the efficiency of DSB-SPB interaction upon induction of a single DSB. Cnm67-CFP and Ddc2-RFP were used as SPB and DSB markers respectively. D1, D2 and D3 distances in wild-type and cdc14-1 cells were tracked using the maximum projection of three z-planes images at 15-seconds intervals over period of 7.5 minutes. A total of 32 time-lapses for each strain were measured. A representative picture is shown. Examples of cells defective in DSB-SPB interaction are marked with arrows. Scale bar: 3μm.

C) An RFP-marked I-SceI recognition site is re-localized to the SPBs after expressing the endonuclease. Cells harbouring a TetO array adjacent to the I-SceI site and a plasmid containing the endonuclease under the control of the galactose promoter were grown overnight in SC-Ade prior galactose induction. To check reproducibility with previous results a Rad52-CFP was used. Cnm67 was labelled with the GFP to be used as SPB reporter. D1, D2 and D3 distances were measured in wild-type and cdc14-1 mutants before and after endonuclease expression by using both TetI-RFP and Rad52-CFP foci using the maximum projection of nine z-planes images. Graphs represent the average of three independent experiments. P values were calculated using a 2-tailed unpaired Student t test. A representative picture of a wild-type strain depicting TetI-Rad52-SPB interaction is shown. Scale bar: 3μm.

D) DSB-SPB tethering requires the N-terminus domain of Mps3. Cells expressing a wild-type Mps3, a mps3Δ2-64 and a mps3Δ75-150 fused to the RFP as the sole source of the protein were scored for their ability to enhance DSB-SPB tethering in both wild-type and cdc14-1 backgrounds. Ddc2-YFP was used as DSB reporter. Measurements were carried out using a maximum projection of nine z-planes images. Graphs represent the average distribution of D1, D2 and D3 of three independent experiments. At least 100 cells for each experiment were scored. P values were calculated using a 2-tailed unpaired Student t test.

E) DSB-SPB interaction involves a proficient DNA damage checkpoint activation. D1, D2 and D3 distances were scored in wild-type, sml1Δ and sml1Δ rad53Δ backgrounds using Ddc2-GFP and Spc110-RFP as DSB and SPB markers respectively. Measurements were performed by using a maximum projection of nine z-planes images. Graphs denote the average distribution of D1, D2 and D3 from three independent experiments where at least 100 cells for each sample were scored. P values were calculated using a 2-tailed unpaired Student t test.

Data information: DSB, Double Strand Break. SPB, Spindle Pole Body. DAPI, 4´,6-Diamidine-2´-phenylindole dihydrochloride.