Nucleosome positioning in mouse embryonic stem cells: lessons from fluorescence microscopy studies of living cells and genome-wide mapping by DNA sequencing
09/10/2012 - Room C209/10 at 14:00 - External Seminar
(DKFZ & BioQuant Center )
The location of nucleosomes on the DNA is important for controlling access to the associated DNA: Binding of protein factors to the 145–147 base pairs of DNA wrapped around the histone octamer core is frequently impeded, while the linker DNA between nucleosomes is more easily accessible. A class of molecular machines referred to as chromatin remodelers can actively translocate or evict nucleosomes in an ATP-driven process. Thus, the positioning of nucleosome represents a regulatory mechanism for controlling DNA access.
We combine fluorescence microscopy techniques for measuring chromatin interactions of remodelers in living cells with DNA-sequencing based genome-wide mapping of nucleosomes in mouse embryonic stem cells. The results obtained in stem cells are compared to their neural progenitor and embryonic fibroblast counterparts to assess features associated with nucleosome positioning during lineage commitment.