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In 1959, David Baltimore was one of Cold Spring Harbor's first undergraduate research students.
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Howard Temin, 1964.
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Howard Temin in his office at the University of Wisconsin at Madison, 1973.
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Howard Temin being interviewed after winning the 1976 Nobel Prize for Physiology or Medicine.
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Howard Temin, 1987.
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(1 of 4) A series of electromicrographs showing the infection of H-9 cells with the MN strain of HIV-1 virus. Magnification including computer enhancements are approximately 100,000 times. A mature round virus particle is sitting next to the cell ready for infection. Note the visible inner core.
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(2 of 4) Virus particle is fusing with the cell membrane and about to empty its contents into the cell. Note the visible inner core.
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(3 of 4) Virus particle budding out from the cell. Although similar to the previous micrograph, the inner core is not as dense and therefore this is an "immature" viron budding out as opposed to a mature virus fusing in to infect a cell.
Audio Glossary
RetrovirusVideo Interviews
Currently President of Caltech University, David Baltimore did work in virology in the late '60s that led to the discovery of reverse transcriptase, and new insight into the life cycle of retroviruses.
Clip 1 (0:53)
Viruses and the genesis of the reverse transcriptase idea.
Clip 2 (0:58)
Isolating reverse transcriptase — the experiment.
Clip 3 (0:24)
Reactions to Howard Temin's idea of retroviral RNA being transcribed into DNA before integration.
Clip 4 (1:35)
Definition of retrovirus.
Clip 5 (0:53)
Use of retroviruses in genetic therapy.
David Baltimore, Howard Temin and Renato Dulbecco shared the 1975 Nobel Prize in Physiology or Medicine for the discoveries concerning the interaction between tumor viruses and the genetic material of the cell. DAVID BALTIMORE (1938-)
David Baltimore was born in New York City. As a high school student, he participated in the Jackson Memorial Laboratory research program in Bar Harbor, Maine. It was his first experience working in a biology research lab and interacting with scientists, and it was the start of his research career. Baltimore studied biology and chemistry at Swarthmore College. In 1959, the summer of his third year at Swarthmore, Baltimore became one of the first undergraduate research students at Cold Spring Harbor Laboratory. He worked with George Streisinger who introduced him to the "new" field of molecular biology. After graduating in 1960, Baltimore went to the Massachusetts Institute of Technology to do a Ph.D. in biophysics. He became interested in animal viruses and in 1961 left MIT and went to Rockefeller University to continue graduate work with Richard Franklin. Franklin taught a course on animal viruses that Baltimore had taken in Cold Spring Harbor. Franklin had experimental evidence that showed how certain viruses seem to shut down synthesis of cellular RNA and induce synthesis of viral RNA. As a post-doctorate, Baltimore continued to study viral systems, specifically viral RNA synthesis. In 1965, Baltimore became a research associate at the Salk Institute where he worked on poliovirus. He found that the RNA genome of poliovirus became the mRNA message once it entered the cytoplasm. In 1968, Baltimore accepted a position as an associate professor of microbiology at MIT. By this time, he began to suspect that not all RNA viruses replicated in the same manner. Baltimore knew about Howard Temin's DNA provirus hypothesis that viral RNA was a template to make viral DNA, which then became the template for the synthesis of progeny viral RNA. In the '60s, this was a radical idea and a clear departure from the accepted Central Dogma of DNA to RNA to protein. Given his own suspicions, Baltimore thought Temin's theory was logical and was able to prove it by finding the RNA-dependent DNA polymerase, later named reverse transcriptase in RSV and in a mouse tumor virus. Baltimore, Temin and Renato Dulbecco shared the 1975 Nobel Prize in Physiology or Medicine for their discoveries concerning the interaction between tumor viruses and the genetic material of the cell. Baltimore became full professor of biology at MIT in 1972. From 1982-1990, Baltimore was a director, and one of the founders of MIT's Whitehead Institute for Biomedical Research. In 1990, he moved to New York to become president at one of his alma maters, Rockefeller University. After a year as president he stayed at Rockefeller as a professor for three more years. Currently, Baltimore is the president of California Institute of Technology and has been since 1998. HOWARD MARTIN TEMIN (1934-1994)
Howard Temin was born in Philadelphia. His father was an attorney and his mother was involved in educational civic affairs. Temin was interested in biology and during high school, he was accepted into the summer research program at Jackson Memorial Laboratory in Bar Harbor, Maine. Temin spent four summers there learning about the world of biological research. After high school, Temin went to Swarthmore College and majored in biology. In 1955, he went to graduate school at the California Institute of Technology. Although he started in biology, he became more interested in animal virology. His doctorate thesis was on work done on Rous sarcoma virus in Renato Dulbecco's laboratory. After his Ph.D. in 1959, he stayed in Dulbecco's lab for another year as a postdoctoral fellow. During this time, he developed his provirus theory, which hypothesized that RSV and other RNA viruses entered the cell and then made DNA copies of themselves before integrating into the host genome. In 1960, he was offered an assistant professorship at the University of Wisconsin-Madison. During the next four years in his basement laboratory, Temin performed the experiments that proved his provirus theory. He published his results in 1964 and in 1975 shared the Nobel Prize in Physiology or Medicine with David Baltimore and Renato Dulbecco for their discoveries concerning the interaction between tumor viruses and the genetic material of the cell. Temin stayed at the University of Wisconsin-Madison and eventually became a full professor. In 1974 he also became an American Cancer Society Professor of Viral Oncology and Cell Biology. He was also on the editorial boards of several journals: Journal of Virology, Journal of Cellular Physiology, and Proceedings of the National Academy of Sciences. Temin was a well-recognized figure around the University of Wisconsin-Madison campus. He walked or biked to and from work everyday along the same path following the lakeshore. In 1998, the University dedicated the Howard Temin Lakeshore Path in his honor. Although Temin did not smoke, he died in 1994 from lung cancer. | |
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LinksRetrovirusesThis site from the University of Leiceister's Department of Microbiology and Immunology has detailed information about retroviruses. There is also a link to the Microbiology Video Library where you can download Quicktime video clips of HIV replication and maturation. The BodyAn AIDS and HIV information resource with lots of information about the disease. HIV is a retrovirus. Bibliography
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