title: Use of morphology index histograms to quantify populations of the fungal pathogen Paracoccidioides brasiliensis.
abstract: To quantify the dimorphic process in wild and mutant strains of Paracoccidioides brasiliensis, we defined a morphology index (Mi) in terms of the maximum cell length (l), maximum cell diameter (d), and septal diameter (s), according to the equation Mi = 2.13 + 1.13 log10 (ls/d2), whose intercept and slope were such that Mi was around 1 for yeast (spherical) cells or 4 for hyphal (elongated) cells. This discriminatory power was used to quantify morphological population mixtures through Mi histograms. During the temperature-induced dimorphic transition (either way), mean Mi (Mi) varied linearly with time, suggesting a continuity in the process. Also, in wild strains and mutants thereof we found an inverse relationship between Mi and content of both cell wall chitin and 1,3-alpha-glucan.
authors.affiliation: Laboratories of Mycology, Instituto Venezolano de Investigaciones Cient�ficas (IVIC), Apartado 21827, Caracas 1020A, Venezuela.
authors.forename: Gioconda
authors.initials: G
authors.lastname: San-Blas
authors.affiliation: Structural Biology, Instituto Venezolano de Investigaciones Cient�ficas (IVIC), Apartado 21827, Caracas 1020A, Venezuela.
authors.forename: Ra L
authors.initials: RL
authors.lastname: Padr N
authors.affiliation: Structural Biology, Instituto Venezolano de Investigaciones Cient�ficas (IVIC), Apartado 21827, Caracas 1020A, Venezuela.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Alamo
authors.affiliation: Laboratories of Mycology, Instituto Venezolano de Investigaciones Cient�ficas (IVIC), Apartado 21827, Caracas 1020A, Venezuela.
authors.forename: Felipe
authors.initials: F
authors.lastname: San-Blas
mesh_terms: D002473:Cell Wall / Q000737:chemistry; D002686:Chitin / Q000032:analysis; D005936:Glucans / Q000032:analysis; D009024:Morphogenesis; D009154:Mutation; D010228:Paracoccidioides / Q000166:cytology* / Q000235:genetics / Q000254:growth & development*; D010641:Phenotype
chemical_list: D005936:Glucans; D002686:Chitin