Transgenesis in the Rat

The first transgenic experiment was carried out more than 15 yr ago, and transgenesis is now a routine technique for the study of gene and cell function, and the development of animal models of disease. The mouse remains the species of choice for the vast majority of transgenic applications, reflecting the cost-effectiveness of using a small species of high fecundity and rapid generation time. An important factor is the establishment of embryonic stem cells from this species, allowing the development and exploitation of gene “knockout” technology.