Cdc14 phosphatase is an important regulator of mitosis in budding yeast. Cdc14 antagonizes cyclin-dependent kinases and promotes multiple postmetaphase events, including segregation of the ribosomal RNA gene array (rDNA) and the nucleolus assembled around this gene cluster. During most of the cell cycle, Cdc14 is anchored to the nucleolus and kept inactive by binding to Net1 (also known as Cfi1...

We have earlier shown that the typical Didinium nasutum nucleolus is a complex convoluted branched domain, comprising a dense fibrillar component located at the periphery of the nucleolus and a granular component located in the central part. Here our main interest was to study quantitatively the spatial distribution of nucleolar chromatin structures in these convoluted nucleoli. There are no "c...

The behavior of the nucleolus during mitosis was studied by electron microscopy in neuroblast cells of the grasshopper embryo, Chortophaga viridifasciata. Living neuroblast cells were observed in the light microscope, and their mitotic stages were identified and recorded. The cells were fixed and embedded; alternate thick and thin sections were made for light and electron microscopy. The interp...

To understand how nuclear machineries are targeted to accurate locations during nuclear assembly, we investigated the pathway of the ribosomal RNA (rRNA) processing machinery towards ribosomal genes (nucleolar organizer regions [NORs]) at exit of mitosis. To follow in living cells two permanently transfected green fluorescence protein-tagged nucleolar proteins, fibrillarin and Nop52, from metap...