Aim. In order to get more information about organization of active chromatin hubs and their role in the regulation of gene transcription we have studied the spatial organization of the α-globin gene domain in cultured chicken erythroblasts. Methods. The chromosome conformation capture (3C) protocol was employed to analyze the 3D configuration of the chicken α-globin gene domain. Results. We have demonstrated that in the same cell population the chicken domain of α-globin gene may be organized in two different active chromatin hubs. One of them appears essential for the activation of the α-globin gene expression while the other – for the activation of TMEM8 gene which constitutes a part of the α-globin gene domain in chicken, but not in human and other mammals. Importantly, two regulatory elements participate in the formation of both active chromatin hubs. Conclusions. The assembly of the same genomic area into two alternative chromatin hubs which share some regulatory elements suggests that active chromatin hubs are dynamic rather than static, and that regulatory elements may shuttle between different chromatin hubs.

Keywords: active chromatin hub, globin gene, genomic domain, chromosome conformation capture