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Nobel Prize in Chemistry Awarded for DNA Repair Research

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Three scientists whose work greatly advanced our understanding of DNA repair have won the 2015 Nobel Prize in Chemistry. They share the prize equally. 

Their discoveries, the Nobel Prize committee said in a press statement [PDF], "have provided fundamental insights into how cells function, knowledge that can be used, for instance, in the development of new cancer treatments." 

Far from stable or pristine, our DNA is constantly battered by external forces like UV radiation, free radicals, and other carcinogens, along with internal instability. DNA molecules are also constantly changing; your genome is not what it was yesterday. Genetic problems can also arise from the replication of DNA during cell division, which happens in your body several million times a day.

DNA damage is constant; but so is its repair. A legion of proteins monitor your genes, proofreading the genome and making any necessary fixes. Without DNA repair, the Nobel Prize committee said, our genetic material would “disintegrate into complete chemical chaos.” They awarded the prize to three chemists, each of whom identified a different mechanism of repair.

Scientists used to believe that DNA was constant and unchanging. In the 1970s, Tomas Lindahl, of the Francis Crick Institute in the UK, demonstrated that DNA does, in fact, decay—at a rate that should have made the development of life on Earth impossible. Lindahl concluded that the damage must be repaired as quickly as it happens.

Over the next few decades, Lindahl would find some of the molecular mechanisms that carry out these repairs. He outlined the concept of base excision repair, a process by which damaged pieces of DNA are removed from the cell. In 1996, Lindahl successfully re-created the human DNA repair process in vitro.

There are two bacterial systems for fixing damaged DNA. One is dependent on ultraviolet (UV) light, and the other takes place in the dark. Biochemist Aziz Sancar, of the University of North Carolina, Chapel Hill, was awarded one third of the prize for his work illuminating the mechanisms of the dark system. Sancar developed the concept of nucleotide excision repair, the process by which enzymes find UV-damaged nucleotides, then snip them from the DNA strand. This form of repair is essential to our ability to recover from sun damage. 

A defect caused by an error in cell division is called a mismatch. Paul Modrich, a Howard Hughes Medical Institute (Maryland) investigator at Duke University, has spent his career studying the mechanisms of mismatch repair. In the 1980s, Modrich identified, cloned, and mapped numerous enzymes involved in the mismatch repair process. In 1989, he published a report on his successful recreation of the mismatch repair process in vitro. Defective mismatch repair systems are associated with a number of diseases, including a hereditary form of colon cancer.

The work of these awardees may lead to future treatments for cancer. “That is why curiosity-based research is so important,” Paul Modrich told the Nobel Prize committee [PDF]. “You never know where it is going to lead … a little luck helps, too.”

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11-Year-Old Creates a Better Way to Test for Lead in Water
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In the wake of the water crisis in Flint, Michigan, a Colorado middle schooler has invented a better way to test lead levels in water, as The Cut reports.

Gitanjali Rao, an 11-year-old seventh grader in Lone Tree, Colorado just won the 2017 Discovery Education 3M Young Scientist Challenge, taking home $25,000 for the water-quality testing device she invented, called Tethys.

Rao was inspired to create the device after watching Flint's water crisis unfold over the last few years. In 2014, after the city of Flint cut costs by switching water sources used for its tap water and failed to treat it properly, lead levels in the city's water skyrocketed. By 2015, researchers testing the water found that 40 percent of homes in the city had elevated lead levels in their water, and recommended the state declare Flint's water unsafe for drinking or cooking. In December of that year, the city declared a state of emergency. Researchers have found that the lead-poisoned water resulted in a "horrifyingly large" impact on fetal death rates as well as leading to a Legionnaires' disease outbreak that killed 12 people.

A close-up of the Tethys device

Rao's parents are engineers, and she watched them as they tried to test the lead in their own house, experiencing firsthand how complicated it could be. She spotted news of a cutting-edge technology for detecting hazardous substances on MIT's engineering department website (which she checks regularly just to see "if there's anything new," as ABC News reports) then set to work creating Tethys. The device works with carbon nanotube sensors to detect lead levels faster than other current techniques, sending the results to a smartphone app.

As one of 10 finalists for the Young Scientist Challenge, Rao spent the summer working with a 3M scientist to refine her device, then presented the prototype to a panel of judges from 3M and schools across the country.

The contamination crisis in Flint is still ongoing, and Rao's invention could have a significant impact. In March 2017, Flint officials cautioned that it could be as long as two more years until the city's tap water will be safe enough to drink without filtering. The state of Michigan now plans to replace water pipes leading to 18,000 households by 2020. Until then, residents using water filters could use a device like Tethys to make sure the water they're drinking is safe. Rao plans to put most of the $25,000 prize money back into her project with the hopes of making the device commercially available.

[h/t The Cut]

All images by Andy King, courtesy of the Discovery Education 3M Young Scientist Challenge.

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Hulton Archive/Getty Images
6 Radiant Facts About Irène Joliot-Curie
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Hulton Archive/Getty Images

Though her accomplishments are often overshadowed by those of her parents, the elder daughter of Marie and Pierre Curie was a brilliant researcher in her own right.


A black and white photo of Irene and Marie Curie in the laboratory in 1925.
Irène and Marie in the laboratory, 1925.
Wellcome Images, Wikimedia Commons // CC BY 4.0

Irène’s birth in Paris in 1897 launched what would become a world-changing scientific dynasty. A restless Marie rejoined her loving husband in the laboratory shortly after the baby’s arrival. Over the next 10 years, the Curies discovered radium and polonium, founded the science of radioactivity, welcomed a second daughter, Eve, and won a Nobel Prize in Physics. The Curies expected their daughters to excel in their education and their work. And excel they did; by 1925, Irène had a doctorate in chemistry and was working in her mother’s laboratory.


Like her mother, Irène fell in love in the lab—both with her work and with another scientist. Frédéric Joliot joined the Curie team as an assistant. He and Irène quickly bonded over shared interests in sports, the arts, and human rights. The two began collaborating on research and soon married, equitably combining their names and signing their work Irène and Frédéric Joliot-Curie.


Black and white photo of Irène and Fréderic Joliot-Curie working side by side in their laboratory.
Bibliothèque Nationale de France, Wikimedia Commons // Public Domain

Their passion for exploration drove them ever onward into exciting new territory. A decade of experimentation yielded advances in several disciplines. They learned how the thyroid gland absorbs radioiodine and how the body metabolizes radioactive phosphates. They found ways to coax radioactive isotopes from ordinarily non-radioactive materials—a discovery that would eventually enable both nuclear power and atomic weaponry, and one that earned them the Nobel Prize in Chemistry in 1935.


The humanist principles that initially drew Irène and Frédéric together only deepened as they grew older. Both were proud members of the Socialist Party and the Comité de Vigilance des Intellectuels Antifascistes (Vigilance Committee of Anti-Fascist Intellectuals). They took great pains to keep atomic research out of Nazi hands, sealing and hiding their research as Germany occupied their country, Irène also served as undersecretary of state for scientific research of the Popular Front government.


Irène eventually scaled back her time in the lab to raise her children Hélène and Pierre. But she never slowed down, nor did she stop fighting for equality and freedom for all. Especially active in women’s rights groups, she became a member of the Comité National de l'Union des Femmes Françaises and the World Peace Council.


Irène’s extraordinary life was a mirror of her mother’s. Tragically, her death was, too. Years of watching radiation poisoning and cancer taking their toll on Marie never dissuaded Irène from her work. In 1956, dying of leukemia, she entered the Curie Hospital, where she followed her mother’s luminous footsteps into the great beyond.


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