Nuclear Architecture and Gene Expression


Gene positioning and regulation of nuclear architecture are thought to influence gene expression. Soft X-ray tomography (SXT) imaging shows that silent olfactory receptor (OR) genes from different chromosomes in mouse olfactory neurons converge in a small number of heterochromatic foci. These foci are OR exclusive and form in a differentiation-dependent manner specific to cell type. OR gene aggregation is developmentally synchronous with the downregulation of the lamin B receptor (LBR) and can be reversed by ectopic LBR expression in mature olfactory neurons. LBR-induced reorganization of nuclear architecture and disruption of OR aggregates perturbs the singularity of OR transcription and disrupts the olfactory neurons’ targeting specificity. These observations indicate spatial sequestering of heterochromatinized OR family members as a basis of monogenic and monoallelic gene expression. This research was conducted using resources at the Advanced Light Source at Lawrence Berkeley National Laboratory.


Clowney, E. J., et al. 2012. “Nuclear Aggregation of Olfactory Receptor Genes Governs Their Monogenic Expression,” Cell 151, 724–37. (Reference link)