Life / Neuroscience & Psychology

Circadian Clock Genes

Fruit flies with faster, slower or no daily rhythm led to the period gene, cloned in 1984; its feedback loop is the cell's 24-hour clock (Nobel Prize 2017).

In 1971 Ronald Konopka and Seymour Benzer found fruit-fly mutants of one gene, period, with a shorter, longer or absent daily rhythm. In 1984 the labs of Michael Young and of Jeffrey Hall with Michael Rosbash cloned it, and later work showed that the PER protein feeds back to switch off its own gene, a loop that takes about a day. Mammals use the same machinery, run from a master clock in the hypothalamus, and mutations in the human PER2 gene cause a family sleep-timing disorder. Hall, Rosbash and Young received the 2017 Nobel Prize in Physiology or Medicine.