Skip to main content
. 2019 Aug 8;47(18):9666–9684. doi: 10.1093/nar/gkz651

Figure 1.

Figure 1.

Mutagenic ssDNA accumulates at multiple positions along BIR track. (A) BIR is initiated by HO endonuclease at MATa in a yeast strain disomic for chromosome (Chr) III. Following the DSB, the broken chromosome (top) invades the homologous chromosome (containing MATα-inc, bottom) initiating BIR that progresses for ∼100 kb to the end of the chromosome. A base substitution reporter, ura3-29, was inserted at different positions of the donor chromosome (0kb (‘MAT’), 16kb, and 90kb away from MATα-inc). (B) The rate of Ura+ mutations at Ori1-oriented ura3-29 before (0 hour) and after (7 hours) BIR in the presence (or absence) of 1.5 mM MMS. The median values of the mutation rates calculated for ≥6 experiments are indicated above the bars. Asterisks and psi-symbols indicate statistically significant differences from No-DSB (0 h) and from no-MMS respectively. Absence of symbols indicates no statistical difference between groups. See Supplementary Table S2 for P-values, description of statistical analysis, 95% CI of the medians, as well as for BIR efficiencies. Under the graph: schematics illustrating guanine (G*) in the mutant position of Ori1-oriented ura3-29 included into ssDNA accumulated during BIR leading strand synthesis. (C) Ura+ mutation rates before and after BIR for Ori2 oriented ura3-29, where cytosine (C*) in the mutant position is included into leading strand ssDNA. See (B) for other details. (D) Ura+ rates for Ori2 ura3-29 inserted at various Chr. III positions following BIR in the presence of APOBEC3A containing plasmid (A3A) or empty vector (EV). Asterisks and pound-symbols indicate statistically significant differences from No-DSB (0h) and from no-A3A (EV), respectively. See (B) for other details and Supplementary Table S3 for P-values, description of statistical analysis, and 95% CI of the medians. (E) Mutation spectra of BIR-induced Ura+ mutations in Ori2-oriented ura3-29 in the presence or absence of MMS at various positions of the reporter. (F) Mutation spectra of BIR-induced Ura+ at Ori2 oriented ura3-29 in the presence of A3A or empty vector (No A3A).