Abstract
Recent advances in replicative DNA labeling technology have allowed new ways to study DNA replication in living plants. Temporal and spatial aspects of DNA replication programs are believed to derive from genomic structure and function. Bass et al. (2015) recently visualized DNA synthesis using 3D microscopy of nuclei at three sub-stages of S phase: early, middle and late. This addendum expands on that study by comparing plant and animal DNA replication patterns, by considering implications of the two-compartment model of euchromatin, and by exploring the meaning of the DNA labeling signals inside the nucleolus. Finally, we invite the public to explore and utilize 300 image data sets through OMERO, a teaching and research web resource for visualization, management, or analysis of microscopic data.