Sydney Brenner (Cavendish Laboratory, Cambridge), François Jacob (Pasteur Institute, Paris), and Matthew Meselson (Caltech) experimentally demonstrate in 1961 the existence of messenger RNA (mRNA): a short-lived RNA molecule that carries genetic information from DNA to the ribosomes, where proteins are synthesized. The idea had been conceived by Brenner and Crick in April 1960 following a conversation with Jacob about the PaJaMo experiment (Pardee-Jacob-Monod). The experimental work was carried out in summer 1960 in Meselson's laboratory at Caltech, using bacteriophage T2 on E. coli to distinguish old from new ribosomes via density-gradient centrifugation. Jacob and Monod coined the term 'messenger RNA' while analyzing the results. Published in Nature on May 13, 1961, in a joint paper with Watson's group after a request from Watson to delay publication until his team completed their own parallel work.