Deletions, Inversions, Duplications: Engineering of Structural Variants using CRISPR/Cas in Mice

Structural variations (SVs) contribute to the variability of our genome and are often associated with disease. Their study in model systems was hampered until now by labor-intensive genetic targeting procedures and multiple mouse crossing steps. Here we present the use of CRISPR/Cas for the fast (10 weeks) and efficient generation of SVs in mice. We specifically produced deletions, inversions, and also duplications at six different genomic loci ranging from 1.1 kb to 1.6 Mb with efficiencies up to 42%. After PCR-based selection, clones were successfully used to create mice via aggregation. To test the practicability of the method, we reproduced a human 500 kb disease-associated deletion and were able to recapitulate the human phenotype in mice. Furthermore, we evaluated the regulatory potential of a large genomic interval by deleting a 1.5 Mb fragment. The method presented permits rapid in vivo modeling of genomic rearrangements. [Display omitted] •CRISVar allows the efficient generation of structural variations in ESCs•ESCs carry duplications, inversions, deletions, or different combinations thereof•ESC clones with specific SVs generate germline transmitting chimeras Kraft et al. now present a 10-week-long protocol to engineer deletions, inversions, and duplications over a megabase in mice. The authors generate ESCs carrying SVs and show that mice with deletion of Laf4 recapitulate a human malformation.