Light induced expression of gRNA allows for optogenetic gene editing of T lymphocytes in vivo.
                            
                                blue
                            
                            
                                EL222
                            
                            
                                
                                    HEK293FT
                                
                            
                                
                                    HEK293T
                                
                            
                                
                                    mouse in vivo
                                
                            
                                
                                    mouse T cells
                                
                            
                            
                                Transgene expression
                            
                                Endogenous gene expression
                            
                                Nucleic acid editing
                            
                            
                            
                            
                            
                        
                        
                        
                        
                            Abstract:
                            There is currently a lack of tools capable of perturbing genes in both a precise and spatiotemporal fashion. CRISPR’s ease of use and flexibility, coupled with light’s unparalleled spatiotemporal resolution deliverable from a controllable source, makes optogenetic CRISPR a well-suited solution for precise spatiotemporal gene perturbations. Here we present a new optogenetic CRISPR tool, BLU-VIPR, that diverges from prevailing split-Cas design strategies and instead focuses on optogenetic regulation of gRNA production. This simplifies spatiotemporal gene perturbation and works in vivo with cells previously intractable to optogenetic gene editing. We engineered BLU-VIPR around a new potent blue-light activated transcription factor and ribozyme-flanked gRNA. The BLU-VIPR design is genetically encoded and ensures precise excision of multiple gRNAs from a single mRNA transcript, allowing for optogenetic gene editing in T lymphocytes in vivo.