Journal of Cell Science, Vol 66, Issue 1 297-308, Copyright © 1984 by Company of Biologists

JOURNAL ARTICLES

The presence and location of sporopollenin in fruiting bodies of the cellular slime moulds

Y Maeda

The presence of an acetolysis-resistant polymer (sporopollenin) in the cellular slime moulds is demonstrated. This polymer is located on the stalk sheath of fruiting bodies as a bundle of fine fibrils (4-5 nm diameter). The location and structure of sporopollenin in spores are shown to vary considerably, depending upon the species. In Polysphondylium violaceum spores, sporopollenin is composed of fine spicules (4-5 nm in diameter, 25-50 nm long) that cover both the outermost layer of spore wall and the inner surface of the cell membrane. The sporopollenin of Dictyostelium discoideum spores is located preferentially close to the inner surface of the cell membrane, forming a mass of electron-opaque fine granules (4-5 nm in diameter). D. mucoroides spores, however, appear not to possess a tight network of sporopollenin, since they were less resistant to acetolysis than those of the other species. The biological significance of the results is discussed with special reference to fruiting body formation.