How have scientists historically identified oncogenes?

Question

Quizplus · Accepted Answer

Scientists historically have identified oncogenes by introducing the DNA suspected of containing the oncogene into cultured cells and looking for altered growth properties. This is accomplished by creating recombinant DNA molecules in which oncogene sequences are coupled to potent promoters that drive high levels of gene transcription. Introduction of these recombinant DNA molecules into cells can lead to tumorigenic transformation of the cells, allowing scientists to identify the oncogene.

How Have Scientists Historically Identified Oncogenes