LAUSR

Genetically engineered mouse (GEM) models have been revolutionizing the biomedical studies on deciphering the physiological roles of genes in vivo. In addition to deactivating a gene in mice, diverse strategies have been created to monitor gene expressions and molecular dynamics of specific proteins in vivo. Although gene targeting in mouse embryonic stem (ES) cells was essential for the precise engineering of the mouse genome over almost three decades, this process is a time-consuming, expensive, and laborious one. These days, new technologies that directly apply engineered endonucleases, such as zinc-finger nucleases (ZFNs), Transcription Activator-Like Effector (TALE) Nucleases (TALENs), and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system, into the mouse zygotes are enabling us to rapidly replace conventional gene targeting in mouse ES cells. In this chapter, we will describe the principles of reporter mouse strains and the recent advances in generating them using engineered endonucleases.