Transcription and Translation

I discovered this wonderful website: Peoples Archives. In it you'll find interviews with some of the greatest thinkers of the 20th century. I just finished listening to Sydney Brenner and Francis Crick and am now listening to Renato Dulbecco.

Dulbecco, a protege of Giuseppe Levi, moved to Salvador Luria's Lab at the University of Indiana in 1947. Like many of the founders of Molecular Biology, Dulbecco started off by studying phage. Phages are to bacteria what viruses are to our cells. Back then the greatest mystery of all was the nature of the unit of inheritance (i.e. genes). Phages were seen as the simplest, most striped-down version of a gene; the idea was that if you understood phages you could figure out the nature of inheritance. In fact another member of the Luria lab went on to discover the nature of the gene, this person was none other than Jim Watson.

In Luria's lab, Dulbecco discovered that UV light reactivated dormant phages. When phages infect, they either reproduce in the host (called the lytic cycle) or integrate themselves into the host's genome and become dormant. When UV hits bacteria, dormant phages are reactivated and reenter the lytic cycle. This result was the first hint that UV caused DNA damage. Here is a perfect example how basic research can lead to fantastic serendipitous results.

Listen to the discovery of photoreactivation (parts I and II).

Dulbecco's work caught the attention of the great Max Delbruck who invited Dulbecco to join his lab at Caltech. Combining tissue culture techniques he learned from Levi, and phage techniques he learned with Luria, Dulbecco developed an assay to study mammalian viruses. In fact if you've ever grown tissue culture cells with DMEM - Dulbecco's Modified Eagle Media, well in a way you are Dulbeccos' protege. His work (and that of his student, Howard Temin and his collaborator, David Baltimore) on Rous Sarcoma Virus and SV40, led to a Nobel prize for "the interaction between tumour viruses and the genetic material of the cell". This work led to the discovery of the first oncogenes.