Knockout Rat - Research Use

Research Use

Mice, rats, and humans share all but approximately 1% of each other's genes making rodents good model organisms for studying human gene function. Both mice and rats are relatively small, easily handled, have a short generation time, and are genetically inbred. While mice have proven to be a useful rodent model and techniques have been developed for routine disruption of their genes, in many circumstances rats are considered a superior laboratory animal for studying and modeling human disease.

Rats are physiologically more similar to humans than are mice. For example, rats have a heart rate more similar to that of humans, while mice have a heart rate five to ten times as fast. It is widely believed that the rat is a better model than the mouse for human cardiovascular disease, diabetes, arthritis, and many autoimmune, neurological, behavioral, and addiction disorders. In addition, rat models are superior to mouse models for testing the pharmacodynamics and toxicity of potential therapeutic compounds, partially because the number and type of many of their detoxifying enzymes are very similar to those in humans. Their larger size makes rats more conducive to study by instrumentation, and also facilitates manipulation such as blood sampling, nerve conduction, and performing surgeries.

Techniques for genetic manipulation are available in the mouse, which is commonly used to model human disease. Although published knockouts exist for approximately 60% of mouse genes, a large majority of common human diseases do not have a knockout mouse model. Knockout rat models are an alternative to mice that may enable the creation of new gene disruptions that are unavailable in the mouse. Knockout rat models can also complement existing transgenic mouse models. Comparing mouse and rat mutants can facilitate the distinction between rodent-specific and general mammalian phenotypes.