An Epigenetic Signature for Monoallelic Olfactory Receptor Expression

Department of Anatomy, University of California, San Francisco, San Francisco, CA 94158, USA.
Cell (Impact Factor: 32.24). 05/2011; 145(4):555-70. DOI: 10.1016/j.cell.2011.03.040
Source: PubMed


Constitutive heterochromatin is traditionally viewed as the static form of heterochromatin that silences pericentromeric and telomeric repeats in a cell cycle- and differentiation-independent manner. Here, we show that, in the mouse olfactory epithelium, olfactory receptor (OR) genes are marked in a highly dynamic fashion with the molecular hallmarks of constitutive heterochromatin, H3K9me3 and H4K20me3. The cell type and developmentally dependent deposition of these marks along the OR clusters are, most likely, reversed during the process of OR choice to allow for monogenic and monoallelic OR expression. In contrast to the current view of OR choice, our data suggest that OR silencing takes place before OR expression, indicating that it is not the product of an OR-elicited feedback signal. Our findings suggest that chromatin-mediated silencing lays a molecular foundation upon which singular and stochastic selection for gene expression can be applied.

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Available from: Gilad Barnea, Apr 22, 2014
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    • "Moreover, we cannot exclude that indirect effects from these genetic manipulations convolute the interpretation of our analysis. However, our previous work showed that, in OSNs, H3K9me3 is deposited almost exclusively on OR genes and pericentromeric and subtelomeric repeats (Magklara et al., 2011). In agreement with this, our RNA-seq data from G9a/Glp KO mice suggest that, by and large, only OR genes are significantly affected by this deletion. "
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