ULTRASTRUCTURE OF THE ASCOSPORE FORMATION OF ARTHRODERMA-SIMII

Ascospore formation of Arthroderma simii was observed using electron m icroscopy. Using scanning electron microscopy, many round asci were ob served inside the gymnothecia obtained by 4 weeks of incubation after mating. Ascospores were produced inside the asci, then discoid-shaped mature ascospores were observed through the degenerate and disrupted a scus cell wall. Disseminated ascospores were observed outside the gymn othecium 7 weeks after inoculation. Using transmission electron micros copy, the enveloping membrane system of two unit membranes invaginated and delimited the cytoplasm. The inner membranes were found to have c hanged into ascospore plasma membranes, whereas the outer membranes an d intercisternal space were changed into ascus cell wall. The subcellu lar events of ascospore formation were found to be essentially similar to those of other dermatophytes.