Chromocenter morphology changes in crwn mutants. (A) Nuclei were imaged from developmentally matched rosette leaves from approximately one month-old plants, cells isolated and stained with DAPI, and nuclei imaged using epifluorescence microscopy. The area and chromocenter number of randomly-selected individual nuclei (n = 47–132) were determined for each genotype, and chromocenter number was plotted against nuclear area. A linear regression line showing the relationship between chromocenter number and nuclear size (as a proxy for endopolyploidy level) was plotted for each genotype. (B) Nuclei were imaged fully expanded rosette leaves from approximately one month-old plants and the chromocenter Aggregation Index (AI) was plotted against the total chromocenter area (μm2).