ASCOSPORE DEVELOPMENT IN HANSENULA ANOMALA

Abstract
The development of ascospores of Hansenula anomala (Hansen) H. & P. Syd. was studied by electron microscopy. Within the young ascus, a double membrane develops around each of the haploid nuclei enclosing mitochondria, oil vacuoles, and endoplasmic reticulum as well. Two ascospore wall layers are deposited within the intercisternal space. The initial wall layer develops centripetally from the extremities of the base, then around the crown of the hat-shaped spore. In many spores, this initial wall is thin or incomplete around the upper portion of the crown. The second wall layer is less electron dense and is formed adjacent to and immediately within the initial layer. At maturity of the spores, no organelles remain in the epiplasm.