An expression microarray approach for the identification of candidate metastable epialleles in the mouse genome

Genetic loci displaying environmentally responsive epigenetic marks, termed metastable epialleles, offer a solution to the paradox presented by genetically identical yet phenotypically distinct individuals. The murine viable yellow agouti (Avy) locus is a well-described metastable epiallele that serves as a visual epigenetic biosensor. The Avy locus exhibits a high R-value or ratio of inter-individual (Vi) to inter-tissue (Vt) variance in gene expression, characteristic of what we term the Agouti Expression Fingerprint. We propose a novel method for identification of candidate metastable epialleles based on the Agouti Expression Fingerprint, defining candidates as loci with R-values greater than 1.5 on expression microarray.

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