2 Harvard Biologists Receive Ledlie Prize

Two Harvard biologists have won the 1969 George Ledlie prize for their study of "repressor molecules" in cellular genetic function.

The winners of the Ledlie prize-which is given every two years to the Harvard faculty member who makes "the most valuable contribution to science, or in any way for the benefit of mankind"- are Walter Gilbert '53, professor of Bio-physics, and Mark Ptashne, lecturer on Biochemistry and Molecular Biology.

The "repressor molecules" that Gilbert and Ptashne studied are proteins that stimulate a few of the genes in each living cell and repress the other genes. Since each cell needs only a few of its thousands of genes to be functioning at any one time, the repressors are neces- sary to turn some of the genes on and keep the rest switched off.

Scientists had speculated for several years that cells must contain some repressor system, but ptashne and Gilbert were the first to show the existence of the actual protein structures. They conducted separate studies--Gilbert concentrating on bacteris, Ptashne working on viruses- and reported their results in 1967.

Gilbert joined the Harvard faculty in 1959, after earning a D. Phil. from Cambridge in 1957 and doing physics research here. He became a full professor last year.

Ptashne graduated from Reed College in 1961 and earned a Ph.D. at Harvard last year. Before joining the Faculty, he was a Junior Fellow in the Society of Fellows here.

President Pusey chooses the prize winners on the advice of his Council of Deans. Since it was started in 1955, the $1600 prize has gone both to scientists and to Faculty members in other fields. Recent winners include Austin W. Scott, Dane Professor of Law, emeritus, for the legal research; Fritz J. Roethlisberger, Wallace Brett Donham Professor of Human Relations, emeritus, for his historic investigations of human relations in industries; and Carroll M. Williams, Bussey Professor of Biology, for research on the juvenile hormone in insects