Comeback of the Rat in Biomedical Research.

Rats were the first mammalian species domesticated for scientific purposes, and they soon became the most widely used animal model in biomedical sciences, including cardiovascular research and behavioral neuroscience. Yet, after the development of technologies to manipulate genes, researchers largely shifted to the use of mice. However, as we lay out with examples from drug addiction, social behavior, and cardiovascular research, rats have experimental advantages over mice. With the introduction of zinc-finger nuclease (ZFN), transcription activator-like effector nuclease (TALEN) methodologies, and, specifically, the clustered regularly interspaced short palindromic repeats (CRISPR) associated system, gene targeting is no longer limited to mice. Development of genetic technologies in rats allows researchers to take advantage of the unique opportunities offered by this species in biomedical research.