Figure 4.
Cells harboring double deletions of YOR193w and PEX25, YOR193w and PEX11, and PEX25 and PEX11 contain greatly enlarged peroxisomes. Ultrastructure of wild-type BY4742 (A), yor193Δ (B), pex25Δ (C), pex11Δ (D), yor193Δ/pex25Δ (E), yor193Δ/pex11Δ (F), and pex25Δ/pex11Δ (G) cells. Cells were grown in YPD medium for 16 h, shifted to YPBO medium, and incubated in YPBO medium for an additional 8 h. Cells were fixed in 3% KMnO4 and proceed for electron microscopy. P, peroxisome; M, mitochondrion; N, nucleus. Bar, 1 μm. (H) Morphometric analysis of peroxisomes. For each strain analyzed, the areas of individual peroxisomes of 100 randomly selected cells were determined using the program analySIS 3.1. Peroxisomes were then separated into size categories. A histogram was generated for each strain depicting the percentage of total peroxisomes occupied by the peroxisomes of each category. The numbers along the x-axis are the maximum sizes of peroxisomes (in square micrometers) in each category, with the exception of the last number, which represents the minimum size of peroxisomes (in square micrometers) in the last category.