Addendum to the Nucleolus

The nucleolus.

When cells are observed by phase contrast microscopy, nucleoli are among the most conspicuous structures. The nucleolus was formally described between 1835 and 1839, but it was another century before it was discovered to be associated with a specific chromosomal locus, thus defining it as a cytogenetic entity. Nucleoli were first isolated in the 1950s, from starfish oocytes. Then, in the early ...

The nucleolus

Are they always about? Not necessarily. They come and go, disappearing in mitosis from late prophase until telophase. During this period, some nucleolar antigens, including RNA polymerase I and topoisomerase I, remain associated with tandemly repeated clusters of ribosomal RNA genes on the condensed chromatin — these chromosomal regions are presumptuously known as nucleolar organising regions (...

Principles of protein targeting to the nucleolus

The nucleolus is the hallmark of nuclear compartmentalization and has been shown to exert multiple roles in cellular metabolism besides its main function as the place of rRNA synthesis and assembly of ribosomes. Nucleolar proteins dynamically localize and accumulate in this nuclear compartment relative to the surrounding nucleoplasm. In this study, we have assessed the molecular requirements th...

Addendum to the Toxicological Profile for [SUBSTANCE]

Addendum to the Toxicological Profile for [SUBSTANCE]