Fig. 4. sar1-1, sec31-1 and pmm1-1 have accumulated ER membranes and dilated nuclear envelope lumens. Electron micrographs of wild-type (A,E), sar1-1 (B,F), sec31-1 (C,G) and pmm1-1 (D,H) cells grown for 4 hours at 36°C. Wild-type cells contain nuclei with normal morphology and few cytoplasmic membranes. sar1-1, sec31-1 and pmm1-1 have dilated nuclear envelope lumens and accumulated ER membranes (B,C,D, arrows). The nuclear envelopes, indicated by arrowheads, are shown at higher magnification to compare the width of the lumen of wild-type with sar1-1, sec31-1 and pmm1-1 strains (compare E with F,G,H). Bar, 1 µm (A-D); 0.2 µm (E-H).
