Figure 8.

S. pombe Hst4p localizes to the nucleolus throughout the cell cycle. A wild-type strain containing N-terminally tagged proA-hst4⁺ under the control of its endogenous promoter (LPY4020) was fixed and stained with DAPI to visualize DNA (top left), with rabbit immunoglobulin G to visualize proA-hst4⁺ (bottom left), and with anti-Nop1p antibodies to stain the nucleolus (bottom right). A merged image of the five cells in different stages of the cell cycle is shown at top right. The DAPI staining is in blue, the proA-Hst4 staining is in green, and the Nop1p staining is in red. In the merged image, the overlap between the proA-Hst4p and Nop1p signals is yellow. The speckled cytoplasmic staining present in the proA-hst4⁺ panel is nonspecific in that it was also seen with secondary antibody alone in wild-type cells not expressing the proA-hst4⁺ construct (our unpublished results). Bar, 2 μm.