Jeffrey C. Hall, Michael Rosbash, and Michael W. Young received the 2017 Nobel Prize in physiology or medicine on Monday because of their research into what handles circadian rhythms – the inner clock that governs how humans, animals, and plants behave throughout the full day and night.

Thanks partly to their discoveries, doctors and researchers now know these day-and-night cycles keep creatures alive by regulating our alertness, sleep patterns, blood circulation pressure, hormones, body’s temperature and when we consume.

Our circadian clock helps to regulate sleep patterns, feeding behavior, hormone release, blood pressure and body temperature. A large proportion of our genes are regulated by the clock. Illustration by Jeffrey C. Hall, Michael Rosbash and Michael W. Young (left to right) won the 2017 Nobel Prize in physiology and medicine. Illustrations by the Nobel Assembly at the Karolinska Institutet


Who are the winners: All three recipients are Us citizens who made their Nobel prize-winning discoveries by dealing with fruit flies, a favorite animal model for genetics and neurobiology tests.

Jeffrey C. Hall, 72, happens to be a geneticist at the University of Maine but conducted his groundbreaking use biologist Michael Rosbash, 73, at Brandeis University near Boston. In the 1980s, the set collaborated with geneticist Michael W. Young, 68, of Rockefeller University in NY to characterize what exactly known as the “period” and “timeless” genes.

Ten years earlier, geneticists, Seymour Benzer and Ronald Konopka had found out that mutations of the period gene disrupted the cycle of regular motions and egg hatching that fruit flies proceed through throughout a 24-hour period.

Some flies experienced their activities on shortened, nine-hour loops, as the schedule for others lengthened to 28 hours.



Hall, Rosbash, and Young finished up pinpointing the positioning of the period and timeless genes within the fruit fly genome and working out what their proteins do.

(Reminder: Genes situated on our DNA make proteins. Proteins constitute our cells, our bodies and everything we do).

What they did: Scientists had known about circadian rhythms since 1729, when astronomer Jean Jacques d’Ortous de Mairan positioned a mimosa plant into a dark room and pointed out that the plant’s leaves still opened and closed at the same times every day.

When the period gene is active, period (PER) messenger RNA is made. This messenger RNA is transported to the cell’s cytoplasm and serves as a template for the production of PER protein. The PER protein accumulates in the cell’s nucleus, where the period gene activity is blocked. This gives rise to the inhibitory feedback mechanism that underlies a circadian rhythm. Illustration by the Nobel Assembly at the Karolinska Institutet


Through some breakthroughs, Hall, Rosbash, and Young showed these internal clocks are self-regulated. In the early morning, sunlight switches on the “period” gene, which starts to create its protein.

This protein accumulates in the cytoplasm, the chunky space inside our cells that surrounds the nucleus where our DNA and the period gene housed.

Hall and Rosbash discovered that period protein developed each day until nightfall when their levels started to steadily drop. Dawn broke when, period proteins vanished, and the cycle repeated itself.

They hypothesized that the period protein was crossing into the nucleus to shut down its gene in some way, in what they dubbed a transcription-translation opinions loop.

Young prolonged the ongoing work by uncovering two more protein, named “timeless,” that was accountable for escorting the period protein into the nucleus.

Young’s laboratory also identified another protein – called double time – that managed the timing of the destruction of the period proteins.

Why it matters: Their combined work launched a subgenre of molecular biology that centered on circadian rhythm proteins. Although genes change from species to species, transcription-translation feedback networks for circadian rhythms were within a bevy of organisms – from algae to plants to Homo sapiens.

In humans, the production controlled by these clock genes of insulin and other hormones involved in maintaining how our bodies process food. Disruption of the genes through sleep mutation or deprivation alters brain functions and has linked with sleep disorders, depression, bipolar disorder and memory defects.

Out of whack, circadian rhythms increase a person’s risk for cancer also, obesity, diabetes, and other metabolic disorders.


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