Genome engineering in mice using TALEN or CRISPR/Cas9 nucleases

In the course of this work, TALENs were optimized to increase the rate and specificity of site directed gene modifications. Furthermore, mice encoding genomic deletions of 9.3 kb or 3.2 kb in Rab38 could be generated at a frequency of 6-37% through pronuclear microinjection of TALEN or CRISPR/Cas9 nuclease pairs in embryos. Application of the CRISPR/Cas9 system led to deletions of up to 52 kb in vitro. This work shows that even the homozygous excision of large gene segments can be obtained in a single step and contributes to the investigation of human hereditary diseases.