FIG. 6.

Pol δ mutants are proficient for limited DNA synthesis following strand invasion. (A) Schematic representation of the gap repair assay. Following transformation of a gapped plasmid into competent yeast, both ends invade the endogenous chromosomal locus. Repair has to occur by integration to yield a stable Ura⁺ transformant. Repair by integration leads to duplication of sequences from the region of homology between the vector and the native chromosome. (B) Frequency of repair of a gapped plasmid substrate. Frequencies are measured as the number of Ura⁺ transformants per 100 ng of cut DNA divided by the number of transformants per 100 ng uncut DNA transformed. (C) Tenfold serial dilutions of each strain were spotted onto YPD plates and left unirradiated or were irradiated with 400 Gy.