Freeze-fracture replication of cultured Pityrosporum orbiculare.

Skin scrapings from a patient with Pityriasis versicolor were plated on a bile salt medium containing 10% glycerol (for cryoprotection) and Pityrosporum orbiculare was harvested for freeze-fracture replication. Resting and budding cells were senn. The overall pattern of indentation of the plasma membrane towards the cytoplasm was well revealed as a spiral arrangement of major indentations with minor ones disposed more or less at right angles. Hexagonally-arranged particles were not observed. Mitochondria were elongated with constrictions at intervals, and the fracture face of the limiting membrane directed towards the exterior exhibited linear arrays of particles. An unusual type of organelle was also present, viz: a membrane-limited vesicle with regularly-spaced depressions or "dimples".