Fig. 5. Localisation of flp 1p-GFP in SIN mutants. Spores were inoculated into minimal medium containing adenine and leucine, and allowed to germinate (except D1-4). The localisation of flp 1p-GFP was examined in multinucleate cells. (A) cdc7 null allele. (1) Interphase, binucleate cell: note that flp 1p-GFP is present in the nucleolus and on the spindle pole body. (2) Cell undergoing a second mitosis: note the presence of a single medial ring and staining along the spindle. (B) cdc14 null allele. (1) Binucleate cell, early in second mitosis: note the presence of the medial ring, and the spindle staining. (2) Multinucleate interphase cell: note that flp 1p-GFP is present in the nucleolus and on the spindle pole body. (C) spg1 null allele. (1) Mitotic cell: note the presence of two medial rings. (2) Mitotic cell: note the presence of staining along the short spindle and on the spindle pole bodies. (3) Multinucleate interphase cell: note that flp 1p-GFP is present in the nucleolus and on the spindle pole body. (Inset) Binucleate cell early in the second mitosis: note the spindle staining. (D) cdc16 null allele, germinating cells were fixed and processed for indirect immunofluorescence. flp 1p-GFP was detected with rabbit antiserum against GFP (2,4); DNA was detected with DAPI (1,3). Images 1-4 are type I cells. Note that there is no discrete nucleolar or spindle pole body staining of flp 1p-GFP. Spotty aggregates were sometimes observed (arrows). Image 5 is a type II cell, nucleolar and spindle pole body staining of flp 1p-GFP is observed. (E) sid2-1 cdc16::ura4⁺ flp 1-GFPc cells were grown at 25°C, and the GFP fluorescence was observed in living cells. The aggregate observed in cell 2 is shown by the arrow. Images 1 and 3 are phase-contrast views of the cells shown in images 2 and 4, respectively.