Jeffrey Hall

University of Maine

Jeffrey Connor Hall is an American geneticist and chronobiologist, Professor Emeritus of Biology at Brandeis University and later affiliated with the University of Maine. He shared the 2017 Nobel Prize in Physiology or Medicine with Michael Rosbash and Michael W. Young for discovering the molecular mechanisms that control the circadian rhythm. Working primarily with the fruit fly Drosophila melanogaster, Hall and his long-time Brandeis collaborator Michael Rosbash isolated the period (per) gene and showed that its protein product, PER, accumulates during the night and is degraded during the day, establishing the negative-feedback transcription-translation loop that is the heart of the biological clock. Their demonstration that PER protein and per messenger RNA oscillate with a roughly twenty-four-hour period gave the first concrete molecular explanation of how organisms keep internal time and anticipate the day-night cycle. Hall also made foundational contributions to the genetics of Drosophila courtship behavior and the neurobiology of sex-specific behavior. Before the Nobel he received the Genetics Society of America Medal (2003), the Gruber Prize in Neuroscience (2009), the Louisa Gross Horwitz Prize (2011), the Gairdner Foundation International Award (2012) and the Shaw Prize (2013). His pioneering circadian-clock genetics underpins the modern field of chronobiology and remains reference material for sleep, chronotherapy and behavioral-genetics research programs that buy fly genetics, behavioral-monitoring and molecular-clock reagents.