ABSTRACT
This chapter aims to familiarize the reader with the general methodology used in creating transgenic mice and to provide examples of how they have been utilized to study mechanisms of normal and abnormal development, tumorigenesis, and disease. The development of a multicellular organism from a fertilized one-cell embryo is orchestrated by complex cellular, molecular, and genetic processes. The expression of exogenous genetic information in mice is most commonly accomplished through zygotic microinjection. Transgenic mice generated by zygote microinjection can be utilized in the formation of loss-of-function mutations in which molecules designed to inhibit the normal function of an endogenous gene are targeted to specific cell types using specific deoxyribonucleic acid regulatory elements. Perhaps the most significant advancement in transgenic technology has been the advent of embryonic stem cells, and the demonstration that they can contribute to the germ line of chimeras.
