Annals of Botany 73: 609-615, 1994
© 1994 Annals of Botany Company
The Plasma Membrane and Peripheral Cytoplasm of the Green Algal Flagellate, Gloeomonas kupfferi
Department of Biology, Skidmore College, Saratoga Springs, New York, 12866, USA
A morphological analysis of the plasma membrane and peripheral endomembrane components of the unicellular chlamydomonad flagellate, Gloeomonas kupfferi, was performed. Conventional fixation, freeze substitution, and rapid freeze-deep etch processing protocols for electron microscopic analyses revealed the following. The plasma membrane is highlighted by distinct infoldings which do not appear to be sensitive to changes in osmotic or cell cycle conditions. These infoldings are irregularly-spaced and roughly 200-225 nm apart. Each elliptical infolding is 400-440 nm long and 90-115 nm wide. The exoplasmic face (EF) of each infolding is highlighted by an aggregation of 130-160 nm intramembranous particles (imps) that are 9.1-10·5 nm in size. These infoldings are associated with the peripheral endoplasmic reticulum network and microtubular network internally and the inner wall layer externally. It is suggested that these infoldings may be associated with cell wall maintenance.Copyright 1994, 1999 Academic Press
Gloeomonas, plasma membrane, infoldings, freeze fracture