Seeds of Change: The Legacy of Barbara McClintock Immortalized by the USPS

On May 4, the United States Postal Service will issue a set of “American Scientists” commemorative stamps featuring Barbara McClintock, whose Nobel Prize winning research was carried out at Cold Spring Harbor Laboratory. Physicist Richard Feynman, physical chemist Josiah Willard Gibbs, and mathematician John von Neumann are also included.

Barbara McClintock (1902-1992) joined the research staff at Cold Spring Harbor Laboratory in 1942 and spent the next 50 years, until her death at the age of 90, conducting genetic studies with corn that revolutionized the biological and biomedical sciences.

McClintock is best known for her discovery of transposable elements or "jumping genes." Based on her observations—and to the astonishment of most scientists of the day (the late 1940s/early 1950s)—McClintock deduced that segments of DNA can hop from one location in chromosomes to other locations as the result of an ordinary cellular process. Such transposition of DNA was later found by other scientists to occur in virtually all living organisms—from bacteria to humans. Today, transposition is a primary subject of inquiry or serves as a powerful research tool in many laboratories around the world. She was awarded the Nobel Prize for her work in 1983.

Despite her notoriety as the discoverer of jumping genes, McClintock made many other seminal discoveries concerning the behavior of genes and chromosomes. Through her studies of the propensity of the ends of broken chromosomes to fuse with each other, McClintock deduced that the ends of normal, unbroken chromosomes must have a specialized structure that prevents them from being "sticky." Moreover, McClintock uncovered a "chromosome healing" process that converts broken chromosome ends from a sticky to a normal state. This work laid the foundation for what would eventually become an entire field of research regarding the critically important properties of chromosome ends called "telomeres."

Cold Spring Harbor Laboratory is a private, non-profit basic research institution. Under the leadership of Dr. Bruce Stillman, a member of the National Academy of Sciences and a Fellow of the Royal Society (London), more than 330 scientists at the Laboratory conduct groundbreaking research in cancer, neurobiology, plant genetics, and bioinformatics. Cold Spring Harbor Laboratory is one of eight National Cancer Institute-designated basic research centers in the U.S. and the only such center in the tri-state area.

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