Fig. 1
From: Chromatin dynamics of the Klf4 locus in mouse pluripotent cells
Endogenous labeling and live imaging of the Klf4 locus. (a) Overview of the insertion positions for the imaging arrays in and around the Klf4 locus as shown in the IGV genome browser together with the presence of open chromatin (ATAC-seq), total RNApol2 and active histone marks H3K4me3 and H3K27Ac in mESCs. Data were taken from the following publicly available datasets: ATAC-sequencing data of F121.6 mESCs cultured in serum/LIF conditions was downloaded from the 4D Nucleome Data Portal (4DNFI6HY3NE7)20. Chromatin immunoprecipitation coupled to sequencing data (ChIP-seq) of total Pol2 (GSM7187836)21, H3K4me3 (ENCFF240MDV)22 and H3K27Ac (ENCFF163HEV)23 were all from E14 mESCs cultured in serum/LIF conditions. (b) Workflow to implement ANCHOR3 DNA labeling. We used CRISPR/Cas9-mediated homology-directed insertion of ANCH3 arrays followed by expression of OR3-mStayGold with the PiggyBac transposon system. (c) Example image obtained from ANCHOR3 labeled Klf4 promoters in mESCs with a close-up on diffraction limited spots representing a singlet and a doublet. (d) Our biological model system is the naïve-to-primed transition during which Klf4 transcription is downregulated, while housekeeping gene Rad23b stays transcriptionally active.
