Induction and Ultrastructure of the Multicellular (Sclerotic) Morphology in Phialophora dermatitidis

Abstract

Yeastlike cells of P. dermatitidis were induced to form thick-walled, multicellular (sclerotic) bodies under very acidic culture conditions. Phase-contrast microscopy and conventional transmission EM thin sections were used to demonstrate the development of these structures. Observations indicated that the multicellular bodies represented an intermediate vegetative growth form phenotypically arrested between the yeastlike and hyphal morphology. The acidic cultural conditions may have inhibited the event of bud emergence by the yeastlike cells without inhibiting the events of growth, nuclear division and cytokinesis.