Fig. 2. c-Myc-GFP localisation in cells expressing elevated levels of the protein. The c-Myc-GFP distribution pattern changes progressively as its expression level is increased. (A) COS-7 cells were transfected with 1, 2 or 4 µg of the c-Myc-GFP expression vector. The distribution of c-Myc-GFP (green), and fibrillarin, a nucleolar marker (red), in representative cells is shown. Transfected cells were classified into three groups based on the c-Myc-GFP expression pattern as follows: (1) cells with nucleoplasmic c-Myc-GFP (upper panel); (2) cells with c-Myc-GFP in the nucleoli (lower panel, yellow arrows); and (3) cells with nuclear inclusions, which had the highest levels of fluorescence intensity (lower panel, grey arrow). The total number of c-Myc-GFP expressing cells and the number of cells in group 2 and 3 increased as the amount of c-Myc-GFP expression vector was increased. (B) There is a positive correlation between the amount of transfected c-Myc-GFP expression vector, and the ratio of cells with nucleolar (2): nucleoplasmic (1) c-Myc-GFP. The ratios are mean values. Error bars indicate the s.d. (n=5).