Getting poster data...
Mariette van de Corput (Erasmus Medical Center Rotterdam, Rotterdam, Netherlands)Long distance looping of regulatory elements to the gene’s promotor is required to activate transcription of mouse β-globin locus (Fig. 1A). Chromatin Conformation Capture (3C) technique has shown that long distance looping takes place between the DNAse Hypersensitive sites (HSs) and the promotor of the actively transcribing genes. Erythroid progeniotors already show an interaction of 6 HSs of the Locus Control Region, the upstream HS -85/-80 and HS-62/-60Kb and the downstream 3’HS1. Upon EKLF depending differentiation an active chromatin hub (ACH) is formed after which an interaction of the gene’s promotor activates transcription (Fig. 1B-D). We have developed a method to visualize and quantitatively measure changes in 3D structure of undifferentiated (inactive) and differentiated (active) erythroid cells. Thereto 3D DNA-FISH was used followed by high-resolution confocal imaging, image reconstruction by deconvolution and quantitative fluorescent object measurements Results show that the volume of the active β-globin locus is almost two fold decreases as compared to inactive loci. Fluorescent object measurements show similar decrease in size of t