The micronuclear separation spindle. Nuclear pores are not empty perforations but are closed by nonetchable material. The separation spindle must elongate as microtubules lengthen and/or slide against...

A view of the ER on which IMPs are organized into lines, arcs, and circles indicating organization of proteins within the ER membrane and possibly peripheral proteins attached to its cytosolic surface...

Tangential fractures through mature trichocysts. The planes in the paracrystalline stacks are exposed. The body is laced to the membrane but such associations must be severed when the trichocyst is di...

A fracture of an apparently fully formed trichocyst showing that the body of paracrystalline material fills the organelles lumen and is bound to the membrane by a loose array of threads. The membrane,...

The tip of the trichocyst does not expand but remains nail shaped and remains bound to the elongated shaft. TEM taken on 6/7/88 by C. Schroeder with Zeiss 10A operating at 80kV. Neg. 19,800X. Bar = 0....

QF-DE of a crystal whose P-fracture face shows many IMPs similar to the P-face of an acidosome lying nearby and trichocyst as well as trichocyst precursor vesicles. TEM taken by C. Schroeder on 6/3/8...

Quick-freeze deep-etch image of a cytosolic region where trichocysts are developing. Vesicles, even small ones, contain contents that are compacting into paracrystalline form. These vesicles seem to h...

Larger vesicles contain paracrystalline cores that are associated at one end with the trichocyst membrane. This may mean that there is a site on the membrane that promotes paracrystalline formation or...

Released from the cell the trichocyst lengthens and its internal meshwork opens up into an elongated needle. TEM taken on 6/7/88 by C. Schroeder with Zeiss 10A operating at 80kV. Neg. 24,880X. Bar = 0...

A view of microtubular ribbons in which the periodic structure of the tubulin units can be seen along the length of the microtubules. Short bridges link the microtubules side to side within a ribbon. ...