%0 Journal Article
%T Tracking the mechanical dynamics of human embryonic stem cell chromatin
%A Elizabeth Hinde
%A Francesco Cardarelli
%A Aaron Chen
%A Michelle Khine
%A Enrico Gratton
%J Epigenetics & Chromatin
%D 2012
%I BioMed Central
%R 10.1186/1756-8935-5-20
%X We use this method to study how the mechanical properties of chromatin movement in human embryonic stem cells (hESCs) are modulated spatiotemporally during differentiation into cardiomyocytes (CM). Notably, we find that pluripotency is associated with a highly discrete, energy-dependent frequency of chromatin movement that we refer to as a ¡®breathing¡¯ state. We find that this ¡®breathing¡¯ state is strictly dependent on the metabolic state of the cell and is progressively silenced during differentiation.We thus propose that the measured chromatin high frequency movements in hESCs may represent a hallmark of pluripotency and serve as a mechanism to maintain the genome in a transcriptionally accessible state. This is a result that could not have been observed without the high spatial and temporal resolution provided by this novel tracking method.Embryonic stem cells (ESCs) are pluripotent cells that are derived from the inner cell mass of the pre-implantation embryo at the blastocyst stage. They are characterized by their potential to self-renew indefinitely and to differentiate into any of the three germ layers - endoderm, mesoderm and ectoderm [1]. This dual capacity places opposing constraints on the organization of the ESC genome [2]. Self-renewal requires that the ESC genome maintains a cellular memory that specifies its pluripotent capacity, whilst pluripotency relies on the ESC genome being in a highly plastic state so as to have the ability to enter any one distinct differentiation pathway [3]. How these two key functional properties of ESCs are maintained is largely unknown. However, from a structural point of view it is thought that the open conformation of ESC chromatin and hyperdynamic association of chromatin structural proteins are in part responsible [2,4-6].Studies in several systems indicate that ESCs are rich in euchromatin and as differentiation progresses, undergo a rapid reorganization of large areas of the genome to accumulate highly condensed, tra
%U http://www.epigeneticsandchromatin.com/content/5/1/20