BACKGROUND: Chromatin organizational and topological plasticity. and its functions in gene expression regulation. have been strongly revealed by the analysis of nucleolar dominance in hybrids and polyploids where one parental set of ribosomal RNA (rDNA) genes that are clustered in nucleolar organizing regions (NORs). is rendered silent by epigenetic pathways and heterochromatization. https://countryscenesaddleryandpetsuppliers.shop/product-category/felt-saddle-pad/