Fig. 3. Expression of C630 delays entry into mitosis. HeLa cells infected with either a control retrovirus or retroviruses encoding myc-tagged C630 were analysed by flow cytometry and fluorescence microscopy in the presence and absence of nocodazole. (A) Graph plotting the mitotic index following treatment of asynchronous populations with nocodazole for the times indicated showing that the C630 population accumulates mitotic cells slower than the control population. Also shown is data from cells expressing the four CAAX mutants, C:S, V:D, 4 and 150 (see text for details). Each point represents the mean and s.e.m. derived from three independent experiments. (B) Graph plotting the mitotic index following release of cells synchronised at G1/S into nocodazole showing that the C630 population accumulates mitotic cells slower than the control population. (C) Bar graph plotting the proportions of cells in each phase of mitosis showing that expression of C630 does not appear to effect progression through mitosis. Each value is expressed as a percentage of the number of cells in mitosis and represents the mean and s.e.m. derived from three independent experiments in which at least 50 mitotic cells were counted. (D) Representative immunofluorescence images of metaphase and anaphase cells typically observed in control and C630 cultures showing that expression of C630 does not appear to disrupt chromosome alignment or segregation. Tubulin is shown in green, myc-tagged proteins in red and the chromosomes in blue.