Combining the two most powerful biological tools of the 21st century, scientists at the Gladstone Institutes have modified how the genome of induced pluripotent stem cells (iPSCs) is read for the first time using a variation of the CRISPR-Cas9 system. The development offers a major technological advance in creating cell models of genetic diseases.
In a study published in Cell Stem Cell, the researchers used a modified version of CRISPR called CRISPR interference (CRISPRi) to inactivate genes in iPSCs and heart cells created from iPSCs.
Ref: CRISPR Interference Efficiently Induces Specific and Reversible Gene Silencing in Human iPSCs. Cell Stem Cell (10 March 2016) | DOI: 10.1016/j.stem.2016.01.022
Developing technologies for efficient and scalable disruption of gene expression will provide powerful tools for studying gene function, developmental pathways, and disease mechanisms. Here, we develop clustered regularly interspaced short palindromic repeat interference (CRISPRi) to repress gene expression in human induced pluripotent stem cells (iPSCs). CRISPRi, in which a doxycycline-inducible deactivated Cas9 is fused to a KRAB repression domain, can specifically and reversibly inhibit gene expression in iPSCs and iPSC-derived cardiac progenitors, cardiomyocytes, and T lymphocytes. This gene repression system is tunable and has the potential to silence single alleles. Compared with CRISPR nuclease (CRISPRn), CRISPRi gene repression is more efficient and homogenous across cell populations. The CRISPRi system in iPSCs provides a powerful platform to perform genome-scale screens in a wide range of iPSC-derived cell types, dissect developmental pathways, and model disease.