Victor Ambros

Victor Ambros
Life Science
Benjamin Franklin Medal
University of Massachusetts Medical School | Worcester, Massachusetts
With Gary Ruvkun and David Baulcombe, for their discovery of small RNAs that turn off genes. Their pioneering work initiated a paradigm shift in our perception of the ways genes are regulated, and this insight is making possible major new genetic tools for basic research, and for improving agriculture and human health.

Understanding how DNA and RNA work inside plants and animals has far-reaching implications for combating disease, raising virus-resistant crops and extending the longevity of cells—and people. The genes inside cells churn out proteins to govern all their systems—from how to build cellular structures to whether a cell lives or dies—and for decades RNA was thought merely to assist production of those proteins. The paradigm of that understanding was well-entrenched in the 1990s, before the work of Victor Ambros, Gary Ruvkun and David Baulcombe helped turn it upside-down, showing that the role of RNA had a much wider scope. Through their research, done jointly and in parallel, these scientists discovered tiny strands of RNA some 20 nucleotides long, which could turn genes off and prevent them from functioning—gene "silencing." Their work has set off an onslaught of research to study the breadth of important cellular processes influenced by small RNA.

Victor Ambros was born in Hanover, NH in 1953. He attended the Massachusetts Institute of Technology [MIT] for both his S.B. and his Ph.D. in biology—completing the latter in 1979 with studies of the polio virus genome under his research advisor, Nobel laureate David Baltimore. As a post-doc at MIT, in the early 1980s he began to study the roundworm Caenorhabditis elegans hoping that a creature so useful for the study of genetic mutations could teach him about cell division and cell death. He joined the faculty at Harvard in 1985, then moved his lab in 1992 to Dartmouth College, where he remained for about 15 years.

In 1993 Ambros spotted a 22-nucleotide RNA now called lin-4 miRNA. He and Gary Ruvkun showed that it had a functional role in the developmental timing of cells: lin-4 RNA interacted with the first product of a target gene, thus inhibiting its function. At first it was not clear whether such functional RNA might be seen anywhere outside of the worms he was studying, and the research was initially underappreciated. By 1999, however, David Baulcombe's work spotting small (or micro-) RNAs associated with gene silencing in plants helped catapult the work to the forefront. This was also fueled by a report the next year from Ruvkun who found a second miRNA that was present not only in C. elegans, but also in other animals including humans. Soon, many more miRNAs were discovered, and scientists began to research them in earnest, discovering that these snippets help control numerous biological functions including cell development and death, muscle development and oncogenesis.

This year Ambros joined the University of Massachusetts Medical School where he continues to study C. elegans, as well as the fruit fly, to further understand how microRNAs play a role in the temporal control of these animals' development. Ambros is a member of the National Academy of Sciences and his awards include AAAS's Newcomb Cleveland Prize, Brandeis's Lewis S. Rosenstiel Award and the Genetics Society of America Medal for outstanding contributions in the past 15 years.

Information as of April 2008