The son of a painter and an American musician, Jacques Monod (1910–1976) earned his bachelor’s degree in 1931 and, after teaching at the university, received his doctorate in natural sciences in 1941. In the meantime, he accompanied Jean-Baptiste Charcot on an expedition to Greenland (1934), completed an internship at the Roscoff Marine Station (1929), and another with geneticist Thomas Hunt Morgan at the California Institute of Technology (1936). An accomplished music lover, he conducted symphony orchestras during his stay in the United States.
During World War II, he joined the Resistance early on and later served in the French military command.
After the Liberation, he joined the Pasteur Institute as a laboratory director in André Lwoff’s department. In 1954, he became director of the Department of Cellular Biochemistry there.
Published in 1961, his work with François Jacob established that gene activity is finely tuned according to the cell’s needs. They demonstrated the existence and coordinated action of regulatory sequences, repressors, and messenger RNA. This discovery profoundly transformed molecular biology and paved the way for the modern study of genetic regulatory networks. The operon model they proposed in 1961 transformed the understanding of the genome, which is now no longer viewed as a mere collection of genes, but as a set of regulated and coordinated programs.
This discovery had a profound impact on molecular biology by establishing that gene expression is a dynamic and finely regulated process, thereby paving the way for an understanding of the regulatory networks that govern the functioning, adaptation, and differentiation of cells.
In 1967, he was elected professor at the Collège de France, and in 1971 he was appointed director of the Pasteur Institute.
Jacques Monod continued his research on the biochemical regulation of protein activity. Together with Jeffries Wyman and Jean-Pierre Changeux, he formulated the allosteric model, which explains how the binding of a molecule to a specific site can alter the conformation and activity of an enzyme. Monod’s work on allostery fueled his reflections on the regulatory mechanisms of living organisms, reflections he expanded into a philosophical perspective in *Chance and Necessity*, published in 1970, an international bestseller translated into seventeen languages.
The Jacques-Monod Institute is named in his honor and conducts fundamental research in biology.
Entry written by Ronan Le Guen (Collège de France) and Olivier Espéli (CIRB).
