Résumé
In 1961, Francois Jacob and Jacques Monod presented a landmark paper describing the operon model. The meeting held in Institut Pasteur this May to celebrate the 50(th) anniversary of their seminal discovery highlighted the impact their visionary theory has had on our understanding of gene regulation. The concepts they postulated are indeed at the heart of two major mechanisms that underlie the control of gene expression in both prokaryotes and eukaryotes: the regulation of transcription initiation by specific DNA-binding proteins, and posttranscriptional control by noncoding RNAs. The model also promoted the concept of regulatory circuits in biology in general and was a precursor for present-day systems biology.