Fig. 1. A conventional knock-in using homologous gene sequences.

For insertion of target DNA sequences into the desired genome locus, a delivery vector contains 500–1000 bp of the left and right homologous nucleotide sequences on both sides of the target genomic locus. The target sequence can be inserted precisely by inducing HDR after endogenous genomic DNA cleavage. The green box indicates the target sequence in the delivery vector system. The arrowhead indicates the DNA cleavage site.