Ultrastructure of sporulation in the Hemiascomycetes Ascoidea corymbosa, A. rubescens, Cephaloascus fragrans, and Saccharomycopsis capsularis

Abstract

Sporulation in four species belonging to three different families of the Hemiascomycetes is described from serial sections. The results show that in each species the formation of the ascospore wall is initiated at a specialized spindle pole body. Spore delimitation proceeds concurrently with the last nuclear division in the ascus. The findings support the taxonomic position that these species belong to a group that includes the yeasts but that is distinct from the Euascomycetes.