Genome editing in Zebrafish and Medaka

Abstract

Two small ornamental fish, zebrafish and medaka, have become popular model vertebrates suitable for genetic analysis. A number of mutant fish defective in organogenesis and biological responses have been isolated from chemical mutagenesis screens and forward genetic analyses of these mutants have identified novel essential regulators involved in morphological and physiological processes. Recently, remarkable innovations in genome editing technologies, such as zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs) as well as the clustered interspaced short palindromic repeats (CRISPR)/CRISPRassociated (Cas) system, have enabled us to introduce double-strand DNA breaks at target genomic loci, subsequently leading to the disruption of targeted genes (knockout) or their replacement with homologous fragments (knockin). Here, we summarize the usefulness and application of targeted genome modifications in zebrafish and medaka and their relevance to the basic and medical sciences.