Biological Clock Discoveries by 3 Americans Earn Nobel Prize

The discoverers of the 'internal clock' of the body, Nobel Medicine 2017

The winners are Jeffrey C. Hall, Michael Rosbash, and Michael W. Young

US scientists Jeffrey C. Hall, Michael Rosbash and Michael W. Young today won the 2017 Nobel Prize in Medicine, "for their discoveries of the molecular mechanisms that control the circadian rhythm," according to the jury of the Karolinska Institute in Stockholm, responsible for the award. The prize is endowed with nine million Swedish crowns, about 940,000 euros.

Thanks in part to his work, today it is known that living beings carry in their cells an internal clock, synchronized with the 24-hour turns of the planet Earth. Many biological phenomena, such as sleep, occur rhythmically around the same time of day, thanks to this inner clock. Its existence was suggested centuries ago. In 1729, the French astronomer Jean-Jacques d'Ortous de Mairan observed the case of mimosas, plants whose leaves open during the day into the sunlight and close at dusk. The researchers discovered that this cycle was repeated even in a dark room, suggesting the existence of an internal mechanism.

In 1971, Seymour Benzer and his student Ronald Konopka of the California Institute of Technology took a momentous leap in research. They caught vinegar flies and induced mutations in their offspring with chemicals. Some of these new flies had alterations in their normal 24-hour cycle. In some, it was shorter and in others, it was longer, but in all of them, these perturbations were associated with mutations in a single gene. The discovery could have earned the Nobel, but Benzer died in 2007, at age 86, for a stroke. And Konopka died in 2015, at age 68, of a heart attack.

The Nobel, finally, was taken to Hall (New York, 1945), Rosbash (Kansas City, 1944) and Young (Miami, 1949). The three used more flies in 1984 to isolate that gene, baptized "period" and associated to the control of the normal biological rhythm. Subsequently, they revealed that this gene and others self-regulate through their own products - different proteins - generating oscillations of about 24 hours. It was "a change of paradigm", in the words of the Argentine neuroscientist Carlos Ibáñez, of the Karolinska Institute. Each cell had a self-regulating internal clock.

The scientific community has since established the importance of this mechanism in human health. This inner clock is involved in the regulation of sleep, in hormone release, in eating behavior and even in blood pressure and body temperature. If, as occurs in people working in shifts at night, the pace of life does not follow this internal script, can increase the risk of suffering different diseases, such as cancer and some neurodegenerative disorders, says Ibanez. The syndrome of fast time zone change, better known as jet lag, is a clear sign of the importance of this internal clock and its mismatches.

The Karolinska researcher sets an example with a 24-hour cycle, in which the internal clock anticipates and adapts the body's physiology to the different phases of the day. If the day begins with deep sleep and a low body temperature, the release of cortisol at dawn increases blood sugar. The body prepares its energies to face the day. When night falls, with a peak blood pressure, melatonin, a hormone linked to sleep, is secreted.

These inner rhythms are known as circadian by the Latin words circa, around, and dies, day. The scientific community now knows that these "around the clock" molecular dashes emerged very soon in living things and were preserved throughout its evolution. They exist in both single-cell life forms and in multicellular organisms such as fungi, plants, animals, and humans.

At the time of its discovery, Hall and Rosbash were working at Brandeis University in Waltham, and Young was researching at Rockefeller University in New York. Its recognition follows the tonic of the Swedish awards. Men have won 97% of Nobel prizes in science since 1901. In the category of Medicine, statistics improve slightly: 12 of the 214 women are awarded the prize: 5.6%.