Binding partners CBP4a and NumA1 localize to different intranuclear subdomains during mitosis in Dictyostelium . During interphase CBP4a and NumA1 colocalize in the nucleolus (black) while NumA1 also shows nucleoplasmic localization to a lesser extent. During prometaphase, CBP4a (red) reorganizes as nucleoplasmic islands distributed throughout the nucleoplasm while NumA1 (blue) remains at the nuclear periphery but in smaller patches. During metaphase the CBP4a islands localize around the periphery of the nucleoplasm as well as the metaphase plate while NumA1 localizes at the nuclear envelope region and along spindle fibres. This pattern remains constant during anaphase with the exception of the disappearance of the CBP4a islands at the metaphase plate region. During telophase the CBP4a islands begin to enlarge while NumA1 reappears in nucleoli and the nucleoplasm but is still present along the nuclear envelope region. It is not clear if the large CBP4a islands during telophase colocalize with NumA1 in reforming nucleoli .