Abstract
Details of the sequential morphological changes occurring during yeastlike to mycelial-form conversion of the dimorphic pathogen Paracoccidioides brasiliensis are described and illustrated by photomicrographs. Conversion of yeastlike to hyphal morphology was initiated by changing the temperature of incubation from 37 to 23 C. Production by the parent yeastlike cells of elongated buds developing into hyphae started to be conspicuous after 24 hr of incubation at 23 C. After 120 hr of incubation, growth was almost exclusively filamentous. Direct transformation of parent yeastlike cells into hyphae was not observed. Dry weight increased continuously during the conversion process in spite of the gradual disappearance of the parent yeastlike cells. Concurrent studies showed that changes in ribonucleic acid and deoxyribonucleic acid content per unit dry weight are about the same whether the yeastlike cells are undergoing conversion at 23 C or growing normally at 37 C, and that deoxyribonucleic acid synthesis is apparently required for bud formation in both cases.
Full text
PDF
Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- CARBONELL L. M., RODRIGUEZ J. TRANSFORMATION OF MYCELIAL AND YEAST FORMS OF PARACOCCIDIOIDES BRASILIENSIS IN CULTURES AND IN EXPERIMENTAL INOCULATIONS. J Bacteriol. 1965 Aug;90:504–510. doi: 10.1128/jb.90.2.504-510.1965. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Carbonell L. M. Ultrastructure of dimorphic transformation in paracoccidioides brasiliensis. J Bacteriol. 1969 Nov;100(2):1076–1082. doi: 10.1128/jb.100.2.1076-1082.1969. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DROUHET E., ZAPATER R. C. Phase levure et phase filamenteuse de Paracoccidioides brasiliensis; étude des noyaux. Ann Inst Pasteur (Paris) 1954 Oct;87(4):396–403. [PubMed] [Google Scholar]
- HUTCHISON W. C., MUNRO H. N. The determination of nucleic acids in biological materials. A review. Analyst. 1961 Dec;86:768–813. doi: 10.1039/an9618600768. [DOI] [PubMed] [Google Scholar]
- Short E. V., Jr, Warner H. R., Koerner J. F. The effect of cupric ions on the indole reaction for the determination of deoxyribonucleic acid. J Biol Chem. 1968 Jun 25;243(12):3342–3344. [PubMed] [Google Scholar]