Fig. 5. Activating a putative damage checkpoint in G1 delays cutting in orp1 cells. An orp1::ura4⁺/orp1-4 ura4-D18/ura4-D18 h+/h- diploid was sporulated and the spores were germinated in the absence of uracil at the restrictive temperature for orp1-4. Half of the culture was irradiated 4 hours after inoculation and cutting was followed by DAPI staining in both cultures.