The 2015 Nobel prizes announced this week saw Sweden’s Tomas Lindahl, American Paul Modrich and Turkish-born Aziz Sancar sharing the Chemistry prize for work on mapping how cells repair damaged DNA; Japan’s Takaaki Kajita and Canada’s Arthur McDonald winning the Physics awards for their discovery that neutrinos have mass; and Irish-born William Campbell, Satoshi Omura of Japan, and Tu Youyou of China winning the medicine prise for developing pioneering drugs against parasitic diseases.
The awards will be handed out on 10 December, the anniversary of prize founder Alfred Nobel's death in 1896.
Working separately, Lindahl, Modrich and Sancar uncovered a number of mechanisms by which cells repair DNA damage caused by agents including ultraviolet rays from the sun and carcinogenic substances.
In the early 1970s, scientists believed that DNA was an extremely stable molecule, but Lindahl demonstrated that DNA decays at a rate that ought to have made the development of life on Earth impossible. This insight led him to discover a molecular repair mechanism which constantly counteracts the collapse of DNA.
Sancar meanwhile, uncovered the mechanism that cells use to repair ultraviolet ray damage to DNA and Modrich elucidated how the cell corrects errors that occur when DNA is replicated during cell division.
Lindahl, the 29th native of Sweden to become a Nobel laureate, is emeritus director of Cancer Research UK’s Clare Hall Laboratory, part of the UK’s new Francis Crick Institute. Modrich is a researcher at the Howard Hughes Medical Institute and Duke University School of Medicine, and Sancar is at the University of North Carolina, both in the US.
Cracking the neutrino puzzle
Kajita and McDonald discovered that the elusive neutrino weighs something more than nothing.
In the 1950s the two researchers were able to observe that neutrinos from the sun, which were thought to be completely weightless, were not disappearing on their way to Earth; rather, they were “switching between two identities”, a chameleon-like reflex which proved they had mass.
The Nobel committee said the discovery, “changed our understanding of the innermost workings of matter and can prove crucial to our view of the universe”. It showed that the Standard Model, the name given in the 1970s to a theory of fundamental particles and how they interact, cannot be the complete theory of the universe.
Kajita is a professor at University of Tokyo and McDonald professor emeritus at Queen’s University in Kingston, Canada.
The Nobel Prize in Physiology or Medicine 2015 was split, one half going to Campbell and Ōmura, “for their discoveries concerning a novel therapy against infections caused by roundworm parasites” and the other half to Tu, who is the first scientist in China to be awarded a Nobel, “for her discoveries concerning a novel therapy against malaria.”
In the 1970s, Campbell and Omura developed avermectin, the forerunner of ivermectin, which since its approval in 1981, has almost eradicated river blindness and greatly reduced the incidence of lymphatic filariasis.
Delving into ancient Chinese traditional medicine texts, Tu discovered artemisinin in the 1960s and 70s, a drug that has significantly reduced death rates from malaria.
Campbell is currently a research fellow emeritus at Drew University in the US. Satoshi Ōmura is professor emeritus at Kitasato University in Japan and Tu is chief professor at the China Academy of Traditional Chinese Medicine.