Rapid in vivo multiplexed editing (RIME) of the adult mouse liver

Background and Aims: Assessing mammalian gene function in vivo has traditionally relied on manipulation of the mouse genome in embryonic stem cells or perizygotic embryos. These approaches are time‐consuming and require extensive breeding when simultaneous mutations in multiple genes is desired. The aim of this study is to introduce a rapid in vivo multiplexed editing (RIME) method and provide proof of concept of this system. Approach and Results: RIME, a system wherein CRISPR/caspase 9 technology, paired with adeno‐associated viruses (AAVs), permits the inactivation of one or more genes in the adult mouse liver. The method is quick, requiring as little as 1 month from conceptualization to knockout, and highly efficient, enabling editing in >95% of target cells. To highlight its use, we used this system to inactivate, alone or in combination, genes with functions spanning metabolism, mitosis, mitochondrial maintenance, and cell proliferation. Conclusions: RIME enables the rapid, efficient, and inexpensive analysis of multiple genes in the mouse liver in vivo .