Fig. 3. Distribution of HP1, HP1, HP1 and me₃K9-H3 in mouse ES cells. (A) The colored panels on the left show alkaline phosphatase staining, while the gallery on right depicts propidium iodide (PI) and antibody stained (Ab) E14 cells maintained in the presence (+) or absence (–) of LIF. Arrows indicate cells with a speckled pattern. (B) Some of the cells depicted in A magnified 3x. SP, speckled pattern; D, diffuse, `microgranular' pattern. (C) High contrast and high magnification images of HP1, HP1 and HP1 foci (green) counter-stained with PI (red). (D) Morphometric data depicting the proportion of cells exhibiting a speckled phenotype, the average number of foci per cell and the relative size of foci (ratio of particles measuring 2 µm to particles measuring 3-6 µm) in each sample. The data represent averages from at least 50, optically sectioned cells. (E) High contrast and high magnification images of double staining of undifferentiated and differentiated E14 cells with antibodies to HP1 (green) and me₃K9-H3 (red). Bars, 5 µm.