Nucleolar separation from chromosomes during Aspergillus nidulans mitosis can occur without spindle forces.

ABSTRACT: How the nucleolus is segregated during mitosis is poorly understood and occurs by very different mechanisms during closed and open mitosis. Here we report a new mechanism of nucleolar segregation involving removal of the nucleolar-organizing regions (NORs) from nucleoli during Aspergillus nidulans mitosis. This involves a double nuclear envelope (NE) restriction which generates three NE-associated structures, two daughter nuclei (containing the NORs), and the nucleolus. Therefore, a remnant nucleolar structure can exist in the cytoplasm without NORs. In G1, this parental cytoplasmic nucleolus undergoes sequential disassembly releasing nucleolar proteins to the cytoplasm as nucleoli concomitantly reform in daughter nuclei. By depolymerizing microtubules and mutating spindle assembly checkpo

SUBMITTER: Ukil L 

PROVIDER: S-EPMC2669022 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature