FIG. 2.

ubc7Δ, cue1Δ, and doa10Δ cells make aberrant karmellae. Wild-type, ubc7Δ, and cue1Δ cells of strain BY4743 transformed with pAK266 (carrying a galactose-inducible HMG1 gene) were fixed for electron microscopy after 24 h of growth on galactose at 16°C. (A) A representative wild-type cell exhibits a normal karmellae structure, which is labeled K. (B and C) Abnormal membrane proliferations observed in mutants, including disorganized membrane strips that are not closely associated with the nucleus, are indicated with arrows. (D, E, F and G) The lipophilic dye DiOC₆ was used to stain wild-type and deletion cells of strain JRY527 after 14 h of growth on galactose at 16°C. A representative wild-type cell exhibits a normal karmellae structure (D). Mutants show a diversity of abnormal membrane proliferations including loops, whorls, and membrane strips (E, F, and G).