Genome-wide mapping reveals impaired initiation of DNA replication upon induced knockout of RAD51.
(A) Graphs show the distribution of sites of DNA replication initiation across two complete chromosomes in the indicated cell lines, in each case grown in the absence (-RAP) or the presence (+RAP) of rapamycin; MFA-seq signal after cells were incubated with 5mM HU for 8 hours is also indicated. MFA-seq signal is represented by Z-scores across the chromosomes, calculated by comparing read depth coverage of DNA from exponentially growing cells relative to stationary cells; the bottom track for each chromosome displays coding sequences, with genes transcribed from right to left in red, and from left to right in blue. (B) Metaplots of MFA-seq signal found in every chromosome, centred on the previously mapped constitutive DNA replication origin (SSRORI) ±0.15 Mb, in -RAP and +RAP cells, and in the absence (-) or presence of HU (+). (C) Metaplots of MFA-seq signal across 0.15 Mb of sequence from all chromosomes ends in -RAP and +RAP cells, and with (+HU) or without (-HU) growth in the presence of HU. In B and C, p values were determined using Wilcoxon test by comparing -RAP with +RAP cells within each -HU and +HU pair.