CRISPR/Cas9-Mediated Targeted Knockin of Exogenous Reporter Genes in Zebrafish

Genome editing technologies such as ZFN, TALEN, and CRISPR/Cas9 efficiently induce DNA double-stranded breaks (DSBs) at a targeted genomic locus, often resulting in a frameshift-mediated target gene disruption. It remains difficult to perform targeted integration of exogenous genes by genome editing technologies. DSBs can be restored through DNA repair mechanisms, such as non-homologous end joining (NHEJ), microhomology-mediated end joining (MMEJ), and homologous recombination (HR). It is well known that HR facilitates homology-dependent integration of donor DNA template into a targeted locus. Recently, both NHEJ-mediated and MMEJ-mediated targeted integrations of exogenous genes have been developed in zebrafish. This chapter summarizes the application of CRISPR/Cas9-mediated knock-in technology in zebrafish.