ABSTRACT
This chapter addresses how methods in molecular biology and genetic engineering were developed so that researchers can insert genes that code for specific proteins into cells and study them. The ability to amplify pieces of DNA by PCR and subsequently either insert them into host cells to study their protein products or introduce them into bacterial cells to express the proteins and purify them for analysis has radically advanced basic biomedical research. Continuing with new and advanced ways to study genes and their protein products, researchers have also developed sophisticated animal models. In addition to using invertebrate worms, fruit flies, and zebrafish, researchers today rely heavily on the use of transgenic and knock-out mice. This chapter also discusses the development and significance of these models for inserting genes or removing them to study protein function and diseases. Finally, this chapter addresses a novel method called silencing RNA (siRNA) that was developed over the last 20 years to knock-out the expression of a specific cellular protein in cultured cells or animals. SiRNA has revolutionized the ability of biomedical researchers to study protein function in the cell, and in parallel has led to important new clinical trials for a variety of diseases.
