Ultrastructure of spore differentiation in Dictyostelium: the prespore vacuole

Isolation and Characterization of a Prespore Specific Structure of the Cellular Slime Mold, Dictyostelium Discoideum

“…Differentiation of the posterior prespore cells is marked both by the appearance of cytoplasmic granules detected by immunohistochemical staining using antispore serum (TAKEUCHI, 1963) and by the formation of the PSV revealed by electronmicroscopic observations (MAFDA and TAKEUCHI, 1969;HOHL and HAMAMOTO, 1969).…”

“…It was found by SUSSMAN and LOVGREN (1965) and by TELSER and SUSSMAN ( 197 1) that two of the enzymes, UDP-galactose polysaccharide transferase and UDP-galactose-4-epimerase, arc released into the extracellular space during the formation of the fruiting body. On the other hand, electronmicroscopic studies indicated that the contents of the PSV is also released outside the cell during spore formation (HOHL and HAMAMOTO, 1969;MAEDA, 1971).…”

“…The specific substance has been recently identified as an acid mucopolysaccharide (TAKEUCIII, SAKIYAMA and MAEDA, unpublished), which was previously described by WHITE and SUSSMAN (1 963) t o be composed of galactose, galactosamine, and galacturonic acid. On the other hand, electronmicroscopic studies revealed that unique vacuoles were specifically present in the prespore cell, but not in the prestalk cell (MAEDA and TAKEUCHI, 1969;HOHL and HAMAMOTO, 1969). The vacuoles are released outside during the process of spore differentiation, and its contents constitute the spore coat.…”

Synergistic Fruiting Body Construction by Polysphondylium violaceum Mutants

“…The prestalk cells occupy the anterior part of the slug and the prespore cells occupy the posterior part, with a fairly sharp dividing line separating the two regions. Ultrastructural differences distinguishing the two cell types have also been described (Hohl & Hamamoto, 1969 Short communication Takeuchi, 1969). The regional polarizahon of D. discoideum is paralleled by gradients in cyclic AMP (c-AMP) and Ca2+ concentration, with higher concentrations of both substances in the prestalk region of the slug (Maeda & Maeda, 1973;Pan et al, 1974).…”

Disappearance of the Surface Sheath from Dictyostelium discoideum Sorus during Late Culmination.

“…Later, Murata and Ohnishi (1980) reported with a scanning electron microscope (SEM) that the sheath remains at both ends of the sorus, the papilla and the region of transition between the stalk and sorus. In these cases, the spores seem to be integrated into the sorus with a slime matrix found in the space between the spores (Hohl and Hamamoto 1969). By contrast, Watts and Treffry (1976), using SEM indicated that the sheath may hold together the spore mass, because it envelops the whole fruiting body, including the sorus.…”