Nuclear Traffic in Fungal Hyphae: In Vivo Study of Nuclear Migration and Positioning in Aspergillus Nidulans

Mol Microbiol. 1997 Aug;25(4):757-69. doi: 10.1046/j.1365-2958.1997.5131873.x.

Abstract

Nuclear migration and nuclear positioning are fundamental processes in all eukaryotic cells. They are easily monitored during hyphal growth of filamentous fungi. We expressed the green fluorescent protein (GFP) as a fusion protein with the putative nuclear localization domain of the transcriptional activator stuA in nuclei of Aspergillus nidulans and visualized these organelles in living cells. Nuclear staining was observed in interphase nuclei but not during mitosis. Nuclear division, nuclear migration, septum formation and branching were analysed with time-lapse video microscopy during hyphal extension. Hyphae elongated at 0.1-1.2 microm min(-1) and nuclei moved with similar speeds towards the hyphal tip until they had reached a defined position. An individual regulation of nuclear mobility in a given hyphal compartment was observed. Some representative movies are available on the Internet (http://www.blacksci.co.uk/products/journals/molextra.htm). Nuclear positioning was also studied at the molecular level. The ApsA protein, which regulates nuclear migration, was localized at the cytoplasmic membrane in germlings and hyphae by immunofluorescence and GFP tagging. A model of nuclear migration, nuclear positioning and the role of ApsA is presented.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aspergillus nidulans / cytology
  • Aspergillus nidulans / metabolism*
  • Cell Division / physiology
  • Cell Nucleus / chemistry
  • Cell Nucleus / metabolism*
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism
  • Green Fluorescent Proteins
  • Luminescent Proteins / genetics
  • Microscopy, Video
  • Nuclear Localization Signals
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Recombinant Fusion Proteins / genetics

Substances

  • Fungal Proteins
  • Luminescent Proteins
  • Nuclear Localization Signals
  • Nuclear Proteins
  • Recombinant Fusion Proteins
  • apsA protein, Aspergillus nidulans
  • Green Fluorescent Proteins

Associated data

  • GENBANK/AJ003163