JACOB, FRANÇOIS

JACOB, FRANÇOIS (1920– ), French molecular biologist and Nobel laureate. Jacob was born in Nancy, attended the Lycée Carnot, and started his medical studies in Paris. With the German invasion of France in 1940 he joined the Free French Forces in exile and fought in North Africa and Normandy. He was seriously wounded and the damage to his hands destroyed his ambition to become a surgeon. He received the Croix de Guerre and the Croix de la Libération and was made a Compagnon de la Libération, one of France's highest honors. After the war he completed his medical studies (1947) and gained his D.Sc. from the Sorbonne (1954). In 1950 he joined the Pasteur Institute as assistant to andre lwoff . He was appointed laboratory director (1956), head of the Department of Cell Genetics (1960), and professor of cell genetics at the College de France (1964). Jacob's research explored the relationship between bacteriophages (phage) and the bacteria these infect as a model for establishing the fundamental principles of genetic control of protein synthesis. He collaborated with many of the founding fathers of molecular biology, including Elie Wollman, Max Delbruck, Jacques Monod, and sydney brenner . This work defined the operon as the control unit consisting of one or more genes encoding the messenger RNA, which dictates protein synthesis. The operon is controlled by regulatory feedback loops incorporating repressor genes which are in turn controlled by operator genes. The operon can collaborate with other operons on the chromosome and is influenced by signals coming from the cytoplasm or the environment. Thus the potential for cell function and division is determined by the nucleotide sequence in DNA which is responsive to a network of controlling signals. This framework and the supporting experimental principles have formed the   basis for subsequent scientific work on gene action and regulation. He received the Nobel Prize in physiology or medicine (1965) jointly with Andre Lwoff and Jacques Monod. His many honors include the Charles Leopold Mayer Prize of the Académie des Sciences (1962) and foreign membership of the U.S. Academy of Sciences. Jacob is also a distinguished writer on the philosophy and culture of science whose highly regarded books include The Logic of Life (1970) and Of Flies, Mice and Men (1980). His cultural contributions were recognized by the award of the Lewis Thomas Prize (1994). He married the pianist Lise Bloch in 1947. (Michael Denman (2nd ed.)