Fig. 4. Localization of the chromatin (as revealed by GFP-tagged histone; A,C) and the red-fluorescent 170 kDa TRITC-dextrane (B,D) in cleavage embryos injected with wild-type (A,B) or with P446L mutant importin-ß (C,D). Following the injection of wild-type importin-ß, the TRITC-dextrane is excluded from the nuclei that form following mitosis (B). However, following the injection of P446L, the TRITC-dextrane is not excluded from the region of the chromatin following mitosis (D), an indication of the absence of functional NE. Note that the chromatin morphology is hardly affected (C). Bar, 20 µm.