Non-apoptotic chromosome condensation induced by stress: delineation of interchromosomal spaces

Abstract

Chromosomes are known to occupy distinct territories, suggesting the existence of definite borders. Visualization of these borders requires chromatin condensation like that seen in prophase cells. We developed a novel method to induce chromosome condensation in all cells regardless of cell cycle stage using a complex set of stresses. The cells were not apoptotic, as indicated by the absence of DNA damage, maintenance of the intact lamina and scaffold attachment factor A, and by the continuation of metabolic processes as well as proliferative capacity. That the appearance of chromosome condensation did not represent a premature mitotic event was shown by the absence of fibrillarin and Ki67 envelopment of chromosomes, continued protein synthesis and the reversibility of chromosome condensation. That chromosome condensation was achieved was demonstrated by the removal of chromatin from the nuclear envelope and chromosome painting. Specific genetic sites known to be at the surface of chromosomes retained their positions as shown by in situ hybridization. Stress-induced chromosome condensation was used to prove that specific nuclear domains such as ND10 are interchromosomally located and that green fluorescent protein-tagged ND10-associated proteins are useful markers for chromosomal boundaries after adenovirus 5 track formation in vivo. From these observations we conclude that chromosomal territories appear to have boundaries that exclude developing macromolecular aggregates.

DNA viruses and viral proteins that interact with PML nuclear bodies

“…This observation has been repeated in several dierent viral systems (see below), which suggests that the cell handles incoming viral particles and their genomes in a non-random manner. Since PML NBs are located between chromosome territories (Plehn-Dujowich et al, 2000) it could be argued that there is limited space within the nucleus for a viral particle to manoeuvre, but similar ®ndings using transfected plasmids to produce HSV-1 replication centres in the absence of viral particles (Lukonis and Weller, 1997), and parallel results in other viral systems, suggests that these are signi®cant rather than chance associations. There is the very intriguing possibility that the interactions occurring between viral genomes and host factors associated with PML NBs could aect the outcome of a viral infection at its very earliest stages.…”

Lytic but Not Latent Replication of Epstein-Barr Virus Is Associated with PML and Induces Sequential Release of Nuclear Domain 10 Proteins

“…Stress-induced chromosome condensation (SICC) was induced as described elsewhere (43). In brief, D98/HR1 cells grown on coverslips were incubated at 41°C for 20 to 30 min while being covered only with a thin film of medium.…”

Cellular proteins localized at and interacting within ND10/PML nuclear bodies/PODs suggest functions of a nuclear depot

“…By immuno¯uorescence microscopy, ND10 are often found associated with splicing domains or speckles corresponding to the interchromatinic granule clusters and by a method called stress induced chromosome condensation (SICC), they were found in the interchromosomal spaces (Plehn-Dujowich et al, 2000). The position of ND10 may be important for the success of DNA viruses in associating with the structure since viruses appear to traverse the nucleus along the intrachromosomal spaces (Bell et al, 2001;Tang et al, submitted).…”