Figure 4.

Peroxisome induction in respiratory-deficient cells. (A) Overlay between Calcofluor White staining (gray) and GFP peroxisomal marker (green) in representative ρ⁺ and ρ° cells. Each image is a 2-D projection of a 3-D image of the entire cell volume. The images were generated with a fixed exposure time and illumination intensity and a camera with a dynamic range exceeding 3 orders of magnitude. (B) Selected time points from 3-D, time-lapse recordings comparing peroxisome biogenesis in respiratory-competent, respiratory-deficient, and drug-treated cells. The DIC images are taken from an equatorial focal plane, whereas the GFP images are 2-D projections showing all peroxisomes in the image volume above a fixed intensity range. Annotation indicates elapsed time in hours:minutes format from start of experiment. Because the drug-treated cells grow slower than untreated ρ⁺ and ρ^o cells, a later time point is used for the final images in the drug-treated samples.