Title: | Microtubules are dispensable for the initial pathogenic development but required for long-distance hyphal growth in the corn smut fungus Ustilago maydis |
Author(s): | Fuchs U; Manns I; Steinberg G; |
Address: | "Max-Planck-Institut fur terrestrische Mikrobiologie, D-35043 Marburg, Germany" |
ISSN/ISBN: | 1059-1524 (Print) 1059-1524 (Linking) |
Abstract: | "Fungal pathogenicity often involves a yeast-to-hypha transition, but the structural basis for this dimorphism is largely unknown. Here we analyze the role of the cytoskeleton in early steps of pathogenic development in the corn pathogen Ustilago maydis. On the plant yeast-like cells recognize each other, undergo a cell cycle arrest, and form long conjugation hyphae, which fuse and give rise to infectious filaments. F-actin is essential for polarized growth at all these stages and for cell-cell fusion. Furthermore, F-actin participates in pheromone secretion, but not perception. Although U. maydis contains prominent tubulin arrays, microtubules are neither required for cell-cell recognition, nor for cell-cell fusion, and have only minor roles in morphogenesis of yeast-like cells. Without microtubules hyphae are formed, albeit at 60% reduced elongation rates, but they reach only approximately 50 mum in length and the nucleus fails to migrate into the hypha. A similar phenotype is found in dynein mutants that have a nuclear migration defect and stop hyphal elongation at approximately 50 mum. These results demonstrate that microtubules are dispensable for polarized growth during morphological transition, but become essential in long-distance hyphal growth, which is probably due to their role in nuclear migration" |
Keywords: | "Actins/metabolism Bridged Bicyclo Compounds, Heterocyclic/pharmacology Cell Nucleus/physiology Cell Polarity Cytoskeleton/physiology Fluorescent Dyes Hyphae/drug effects/*growth & development Indoles Kinetics Microtubules/*physiology Models, Biological Ph;" |
Notes: | "MedlineFuchs, Uta Manns, Isabel Steinberg, Gero eng Research Support, Non-U.S. Gov't 2005/04/15 Mol Biol Cell. 2005 Jun; 16(6):2746-58. doi: 10.1091/mbc.e05-03-0176. Epub 2005 Apr 13" |