David Baltimore

David Baltimore married Alice Huang in October 1968; they first met while working together at the Salk Institute for Biological Studies. The couple has one daughter. His wife is also a biologist specializing in microbiology and virology.

David Baltimore was born on March 7, 1938, in New York City. His mother, Gertrude Lipschitz, was an atheist, while his father, Richard Baltimore, had been raised as an Orthodox Jew. David observed Jewish traditions like his father.

He graduated from Great Neck High School in 1956. While in high school he spent a summer at the Jackson Laboratory's Summer Student Program in Bar Harbor, Maine, which kindled the teenager’s interest in biology.

He initially decided to major in biology in college but then switched to chemistry. He earned his Bachelor's degree with high honors at Swarthmore College in 1960. During his college days he spent a summer at the Cold Spring Harbor Laboratories working with Dr. George Streisinger which inspired the young man to take up molecular biology.

He entered graduate school at Massachusetts Institute of Technology in biophysics but soon his interest shifted to animal virology. He proceeded to take the animal virus course at Cold Spring Harbor, taught by Dr. Richard Franklin and Dr. Edward Simon. He was highly influenced by Franklin who he joined at the Rockefeller Institute to do his thesis work. He obtained his doctorate in 1964

He also studied for a while with Dr. Jerard Hurwitz at the Albert Einstein College of Medicine to learn about enzymology.

In 1965, he joined the Salk Institute for Biological Studies, California, as a Research Associate. There he worked in association with Dr. Renato Dulbecco and performed important research on the mechanism of replication of the poliovirus.

Along with his colleagues he discovered the mechanism of proteolytic cleavage of viral polyprotein precursors and demonstrated the importance of proteolytic processing in the synthesis of eukaryotic proteins. One of his major works was the discovery that polio produced its viral proteins as a single large polyprotein that was subsequently processed into individual functional peptides.

In 1968, he accepted the position of Associate Professor of Microbiology at the Department of Biology at MIT. One of his colleagues at the Salk Institute for Biological Studies, Alice S. Huang also moved to MIT and the two worked together on vesicular stomatitis virus (VSV).

Over the course of their work Baltimore and Huang demonstrated that VSV, an RNA virus, reproduced itself by means of an unusual enzyme (an RNA-dependent RNA polymerase) that copies RNA by a process not involving DNA. The couple eventually married.

In 1972, Baltimore was awarded tenure as a Professor of Biology at MIT, a post that he held until 1997. In 1973, he also became an American Cancer Society Professor of Microbiology.

In 1970 David Baltimore isolated a reverse transcriptase (RT)—an enzyme used to generate complementary DNA (cDNA)—from two RNA tumor viruses: R-MLV and RSV. It is mainly associated with retroviruses though several non-retroviruses also use the process of RT.

He developed a system of virus classification—now known as the Baltimore classification—that groups viruses into families, depending on their type of genome (DNA, RNA, single-stranded (ss), double-stranded (ds), etc.) and their method of replication.