fluorescence-situ-hybridization-on-dna-halo-preparations-to-reveal

Fluorescence In Situ Hybridization on DNA Halo Preparations to Reveal Whole Chromosomes, Telomeres and Gene Loci

The genome is associated with several structures inside cell nuclei, in order to regulate its activity and anchor it in specific locations. These ...

University of Hertfordshire

The radial spatial positioning of individual gene loci within interphase nuclei has been associated with up- and downregulation of their expression. In cancer, the genome organization may become disturbed due to chromosomal abnormalities, such as translocations or deletions, resulting in the repositioning of genes and alteration of gene expression with oncogenic consequences. In this study, we analyzed the nuclear repositioning of  (also called ), mapping at 7q36.3, in patients with hematological disorders carrying interstitial deletions of 7q of various extents, with a distal breakpoint in 7q36. We observed that  remains at the nuclear periphery, or is repositioned towards the nuclear interior, depending upon the compositional properties of the chromosomal regions involved in the rearrangement. For instance, a proximal breakpoint leading the guanine-cytosine (GC)-poor band 7q21 near 7q36 would bring  to the nuclear periphery, whereas breakpoints that join the GC-rich band 7q22 to 7q36 would bring  to the nuclear interior. This nuclear repositioning is associated with transcriptional changes, with  in the nuclear interior becoming upregulated. Here we report an  rearrangement, involving one single chromosome altering gene behavior. Furthermore, we propose a mechanistic model for chromatin reorganization that affects gene expression via the influences of new chromatin neighborhoods.

Helen A. Foster

Biosciences,
Department of Clinical,
Pharmaceutical and Biological Science,
School of Life and Medical Sciences,
Biosciences, Department of Clinical, Pharmaceutical and Biological Science, School of Life and Medical Sciences

University of Hertfordshire

Fluorescence In Situ Hybridization on DNA Halo Preparations to Reveal Whole Chromosomes, Telomeres and Gene Loci