Fig. (3).

Multiplexed transcriptional gene activation or repression by CRISPR-dCAS9. A) Doxycycline-inducible dCas9 system could allow for precise temporal modulation of genes during the course of the differentiation process. Guide RNAs (gRNAs) of genes to be activated would be cloned into RNA scaffolds that harbor activator-binding motif, whereas gRNAs targeting genes to be repressed, would be cloned into scaffolds with repressor-recruiting motifs. B) The ability to temporally control multiple key TFs using this system could open new opportunities for large scale screenings to ultimately achieve functional HSCs in vitro.