ABSTRACT
Many zoopathogenic fungi grow in more than one morphology. with a saprobic phase usually consisting of hyphae. and a parasitic phase. frequently expressed as yeast. The phenotypic duality of fonn has been tenned dimorphism [1]. Dimorphism is a useful model to examine the basis of morphogenesis and cellular differentiation in eukaryotes. leading to a better understanding of the pathogenic behavior of a given species. and the virulence of strains within it; therefore providing clues for the control of an important group of mycoses which afflict man and animals. Temperature. or nutritional factors, or both are usually the agents which trigger a change in fungal morphology [1]. Few fungi. among them Paracoccidioides brasiliensis. have been studied systematically to search for the molecular and biochemical events leading to dimorphism and eventual expression of pathogenicity.
