title: Hyperbranching induced by cold-shock or snow-flake mutation in Neurospora crassa is prevented by addition of exogenous calcium.
abstract: Hyphal tip growth is a highly polarized process of cell extension, which may be affected by chemical and physical stress. Neurospora crassa exposed to cold-shock lost its polarized growth and dichotomous branches were detected. These effects were not observed in the presence of 500 mM Ca2+. We compared here the morphological pattern of a snow-flake mutant (sn) and the wild-type (wt) exposed to 4 degrees C. Hyphal morphology, nuclei, actin and microtubule distribution were analyzed. No effects on sn hyphal morphology were detected at 4 degrees C. Exogenous Ca2+ converted sn to an essentially wt appearance. The results presented here suggest that sn mutation and cold-shock treatment have affected Ca2+ influx since addition of this cation to sn (30 degrees C) and to wt (4 degrees C) maintained polarized growth and normal nuclear and microtubules distribution.
authors.affiliation: Departamento de Ciências Farmacêuticas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Avenida Zeferino Vaz s/n, CEP 14040-903 - Ribeirão Preto - SP, Brasil.
authors.forename: Cristina Y
authors.initials: CY
authors.lastname: Kawano
authors.forename: Suraia
authors.initials: S
authors.lastname: Said
mesh_terms: D000199:Actins / Q000648:ultrastructure; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002467:Cell Nucleus / Q000648:ultrastructure; D016764:Cell Polarity; D003080:Cold Temperature; D025301:Hyphae / Q000166:cytology / Q000254:growth & development; D008870:Microtubules / Q000648:ultrastructure; D009024:Morphogenesis / Q000187:drug effects / Q000235:genetics; D009154:Mutation; D009492:Neurospora crassa / Q000166:cytology* / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism
chemical_list: D000199:Actins; D002118:Calcium