Functional Centromeres Determine the Activation Time of Pericentric Origins of DNA Replication in Saccharomyces cerevisiae
(A) Replication kinetic profiles of chromosome XIV in WT (top) and rearranged (bottom) strains. Percent replication was monitored across chromosome XIV at 40 (magenta), 45 (orange), 55 (green), and 65 (blue) minutes following release from alpha factor arrest. When the native centromere (yellow circle) is present near ARS1426, a prominent peak is seen in the 40 and 45 minute time samples. In this strain, the peak at ARS1410 is shallow in the 40 and 45 minute samples. When the centromere is repositioned (orange circle) near ARS1410 in the rearranged strain, both the time of appearance and the prominence of the peaks at ARS1410 and ARS1426 are inverted with respect to the WT strain. See Figures S2 and S3 and Datasets S1 and S2 for all chromosomes. (B) Z-score plots of chromosome XIV in WT (black) and rearranged (blue) strains. Replication kinetic profiles from the 40 minute sample were normalized by converting percent replication values to Z-score values (see Materials and Methods). Genomic loci corresponding to ARS1410 and ARS1426 show significant differences in Z-scores. ARS1424 is the next closest active origin to the endogenous centromere residing ∼19 kb to the left. See Figures S4, S5, S6 and Datasets S3 and S4 for all chromosomes and the 45- and 65-minute samples.