Fig. 1.

Ctcf hemizygosity as a model to subtly perturb nuclear homeostasis. a The engineered Ctcf locus contains loxP sites flanking the protein-coding exons of the gene (wild-type (WT), Ctcf ^+/+), which can be removed using Cre recombinase (Ctcf ^+/−). Mouse embryonic fibroblast (MEF) lines were derived from six WT and six Ctcf ^+/− littermates. Quantitative analyses of CTCF binding, transcription, proteome, chromatin state, and chromatin structure were performed in multiple biological replicates (“Methods”). b Validation of CTCF depletion in Ctcf ^+/− MEF cultures. Quantification of Ctcf deletion by qRT-PCR and quantitative western blotting experiments show that there is only partial compensation in the level of CTCF from DNA to RNA to protein