Figure 12

Hypothesis for inferring the mechanism of replication in chloroplast genomes. The schematic shows extension of insights developed in animal mitochondrial genome systems, where deamination gradients have been related to single-strandedness during replication, to the plant chloroplast system. The hypothesis developed here is to test for the presence of local deamination gradients in regions spanning between replication origins (1–6), from which the direction in which the DNA is left single-stranded during replication could be inferred, to arrive at a model for the mechanism of chloroplast replication. The left portion of the image in the top rectangle, demonstrating mitochondrial replication is modified from Figure 1 in [60], and the graph on the right side of this image depicting genome-wide C → T and A → G deamination gradients is modified from Figure 4 in [23], respectively, such as to reflect heavy strand notations.