Ultrastructure of mitotic spindles isolated from a cell division cycle mutant of the yeast, Saccharomyces cerevisiae.
Mitotic spindles were isolated from a temperature-sensitive cell division cycle mutant of Saccharomyces cerevisiae arrested in medical nuclear division by incubation at 36.5 degrees C for 5 h. Cell walls were removed and the resulting sphaeroplasts lyzed on an air water interface. Spindles were collected on electron microscope grids for examination following positive or negative staining. The poles of the spindle consisted of a pair of quadrilaminar spindle pole bodies (SPBs) which measured 160 nm in diameter. The outer, cytoplasmic layer of the SPB was resolved into distinct subunits from which 1 to 3 cytoplasmic microtubules were occasionally seen to emerge. The inner, nuclear, face of the SPB was associated with two families of spindle microtubules; a bundle of 5 to 10 continuous microtubules 1.5 to 2.5 microns long with both ends associated with an SPB, and up to 17 shorter discontinuous microtubules radiating from each SPB and ending at no obvious structure.
D002467:Cell Nucleus / Q000648:ultrastructure; D002843:Chromatin / Q000648:ultrastructure; D008854:Microscopy, Electron; D008870:Microtubules / Q000648:ultrastructure*; D008938:Mitosis; D009154:Mutation; D009685:Nuclear Envelope / Q000648:ultrastructure; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000648:ultrastructure*
D002843:Chromatin