Designer Zinc Finger Nuclease: A Versatile Tool for Genome Editing in Animals

Abstract

In this review, is provided an update on the most popular approaches, including zinc finger nuclease (ZFN)-based gene editing by homologous recombination (HR), gene knockout, non-homologous end joining (NHEJ), and gene therapy in mouse. Zinc finger nucleases (ZFNs) are synthetic restriction enzymes evolved by fusing zinc finger that facilitate genome editing by creating a double-stranded break in DNA at a user-specified location. ZFNs are new tools that promise to radically simplify gene knockout, targeted gene deletions and replacements, because of their high specificities. Most recent strategies for developing ZFNs with customized sequence specificities require the construction of numerous tandem arrays of zinc finger proteins (ZFPs) to target genes specifically, also added more fingers (up to six per ZFN) to specify longer and rare cleavage site. The classical synthetic Cys2His2 zinc finger domains (C2H2 ZFs) with engineered DNA-invoking specificities have shown promise for application in biological research. Current methods of an engineered ZFN design, the important use in modification of the mouse genome, and innovative applications of this technology in mouse will be discussed. Targeted genome inactivation of endogenous immunoglobulin genes in combination with addition of human immunoglobulin genes has been achieved in mice. A light-activated ZFN will competence the conditional generation of gene knock-ins and knock-outs with unique accuracy. ZFNs are useful to generate precisely targeted genome edits resulting in cell lines including somatic cell lines with targeted gene deletions, integrations or modifications. ZFN-mediated site-specific mutagenesis have been proven to be effective in many model organisms – arabidopsis, drosophila, zebrafish, caenorhabditis elegans, rabbit and mouse.
Keywords: Zinc finger nuclease, double-strand base pairs, gene targeting, homologous recombination, non-homologous end joining, gene therapy, animal models