Figure 3.

TEM Observations of ultrathin sections (60 nm) of Wild-Type and Class A Mutant Strains.

Polysaccharide contents of the wild-type CLg1 strain (A), and the 99A7 (B) and 175E12 (C) mutant strains were observed after periodic acid thio-carbohydrazide-silver proteinate staining. Both starch-like granules (white star) and glycogen particles (dots indicated with black arrows) are witnessed in the wild-type strain. Starch granules are missing and substituted by a large amount of glycogen particles in class A mutants. The dark-blue iodine stain from a cell patch of the wild-type strain (framed in [A]) is displayed. By contrast, the absence of starch granules in class A mutants is correlated by a yellow-orange stain of cell patches after spraying iodine vapors (framed in [B] and [C]).