9 Functions and Origins of Retroviral Transforming Genes

Abstract

I. INTRODUCTION
Retroviruses first attracted the attention of experimentalists because of their ability to produce tumors in animals (Rous 1911; Gross 1970), and they were recognized by the late 1950s as useful reagents for analysis of the oncogenic process because of the efficiency with which transformation could be induced and scored in cell culture (Temin and Rubin 1958). Nevertheless, there was no genetic definition of virus components responsible for such biological effects until 1970 (Martin 1970; Vogt 1971; Bader 1972) and no biochemical or immunological definition of the products of retroviral oncogenes until 1977 (Brugge and Erikson 1977). However, during the past 4 years, there has been an extraordinary proliferation of new information about retroviral transforming genes. Several technical advances have propelled this fruitful activity: improved methods for biochemical analysis of viral genomes and mRNAs (Chapters 4 and 5); successful culturing of a variety of cell types, particularly hematopoietic cells (Chapter 8); cloning of retroviral DNA (Chapters 4 and 5); and the production of effective antisera combined with refined procedures for biochemical analysis of proteins (this chapter and Chapter 6). As tales unfolded about the nature and origins of transforming genes of widely used viruses, such as Rous sarcoma virus (RSV), many investigators turned to viruses that had been less commonly studied or even ignored since their original isolation.

A. Viruses with and without onc
As one consequence of this catholic approach, it is now possible to perceive a major division between two types of tumor-inducing retroviruses. On the one...