Yeast-mycelial dimorphism of haploid and diploid strains of Ustilago maydis

Article Abstract:

A study of conditions that stimulate dimorphic transition in Ustilago maydis reveals that pH regulation of the culture media enables mycelial growth of haploid and diploid U. maydis strains. Neutral pH leads to the growth of a homogeneous population of budding yeast-like cells, while acidic pH leads to the development of the mycelial form. The appearance of mycelial cells varies from that of yeast cells, with the nitrogen and carbon sources influencing cell morphology. Culture medium depletion leads to the formation of long, filamentous cells. The functional resemblance between haploid wild-type strains and null b, bW and bE mutants indicates that the regulatory mechanisms controlled by the bE and bW loci are surpassed by growth at low pH.

Physiological aspects, Growth, Yeast, Yeast (Food product), Molds (Fungi), Hydrogen-ion concentration

---

Two chitin synthase genes from Ustilago maydis

Article Abstract:

Conditions that allow the dimorphic transition of haploid strains of the Ustilago maydis fungus in solid or liquid media are described. Two CHS genes of the plant pathogen were cloned to understand their expression during the dimorphic transition and the phenotypic changes that take place in mutants that carry substitutions of these genes. The genes Umchs1 and Umchs2 were identified in the positive clones recovered. The genes' sequence was very similar to the CHS genes already cloned from other fungi, particularly in the central region.

Genetic aspects, Microbiological synthesis, Fungi, Plant cell walls, Cell walls

---

Cloning and disruption of the ornithine decarboxylase gene of Ustilago maydis: evidence for a role of polyamines in its dimorphic transition

Article Abstract:

Reverse genetics was conducted to isolate an ornithine decarboxylase (odc) null mutant of Ustilago maydis. The odc gene was cloned and a conserved PCR amplified product from the U. maydis was synthesized and used to screen a genomic library of the fungus. A high degree of homology was observed in the alignment of its deduced protein sequence. The null mutant exhibited no ODC activity and behaved as a polyamine auxotroph.

Dimorphism (Biology), Dimorphism (Plants), Polyamines, Ornithine decarboxylase, Smut fungi, Smuts (Fungi)

Similar abstracts:

• Abstracts: Persistence of colonization of human colonic mucosa by a probiotic strain, Lactobacillus rhamnosus GG, after oral consumption
• Abstracts: Genetic evidence for hybridization of pallid and shovelnose sturgeon. Characterization of Sox9 in European Atlantic Sturgeon (Acipenser sturio)
• Abstracts: Methods for observing microbial biofilms directly on leaf surfaces and recovering them for isolation of culturable microorganisms
• Abstracts: Effects of temperature and salinity on the survival of Vibrio vulnificus in seawater and shellfish. Multiple Vibrio vulnificus strains in oysters as demonstrated by clamped homogeneous electric field gel electrophoresis
• Abstracts: Relatedness of penicillin-resistant Streptococcus pneumoniae serogroup 9 strains from France and Spain. Electrotransformation of Streptococcus pneumoniae: evidence for restriction of DNA on entry

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.