The role of chromatin condensation during granulopoiesis in the regulation of gene cluster expression

作者：Stejskal Stanislav; Koutna Irena^*; Matula Pavel; Rucka Zdenek; Danek Ondrej; Maska Martin; Kozubek Michal

来源：Epigenetics, 2010, 5(8): 758-766.

DOI：10.4161/epi.5.8.13183

• granulocytes
• immunohistochemistry
• RNA polymerase II
• image analysis
• cell differentiation

Changes in nuclear architecture play an important role in the regulation of gene expression. The importance of epigenetic changes is observed during granulopoiesis when changes in the nuclear architecture are considered a major factor that influences the downregulation of genes. We aimed to assess the influence of chromatin condensation on the regulation of gene expression during granulopoiesis. Based on a previously published microarray analysis, we chose loci with different levels of transcriptional activity during granulopoiesis. Fluorescent in situ hybridization (FISH) and immunofluorescent labeling of RNA polymerase II were used to determine the relationship between the transcriptional activity of gene clusters and their localization within areas with different levels of chromatin condensation. Although active loci were positioned outside of areas of condensed chromatin, downregulation of genes during granulopoiesis was not accompanied by a shift of the downregulated loci to condensed areas. Only the beta-globin cluster was subjected to chromatin condensation and localized to condensed areas. Our results indicate that granulopoiesis is accompanied by a non-random, tissue-specific pattern of chromatin condensation. Furthermore, we observed that the decrease in the quantity of RNA polymerase II correlates with the differentiation process and likely acts in synergy with chromatin condensation to downregulate total gene expression.

• 出版日期2010-12