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2018 | Patrick Allard, et al – Organisms remember ancestral environmental chemical exposure

This new study by the Allard lab reveals that exposure to the plastic chemical Bisphenol A causes a transgenerational impact on fertility that lasts for 5 generations. The authors also dissect the epigenetic machinery behind this effect and were able to reverse the inheritance of the effect. The work can be found in Cell Reports here:  https://www.cell.com/cell-reports/abstract/S2211-1247(18)30637-5

Researchers Identify 44 Genomic Variants Associated with Depression

A new meta-analysis of more than 135,000 people with major depression and more than 344,000 controls has identified 44 genomic variants, or loci, that have a statistically significant association with depression. Of these 44 loci, 30 are newly discovered while 14 had been identified in previous studies. In addition, the study identified 153 significant genes, and found that major depression shared six loci that are also associated with schizophrenia. Results from the multinational, genome-wide association study were published April 26 in Nature Genetics. The study was an unprecedented global effort by over 200 scientists who work with the Psychiatric Genomics Consortium. Co-leaders of the study are Patrick F. Sullivan, MD, FRANZCP, Yeargen Distinguished Professor of Psychiatry and Genetics and Director of the Center for Psychiatric Genomics at the University of North Carolina School of Medicine; and Naomi Wray, PhD, Professorial Research Fellow at the University of Queensland in Australia.

“This study is a game-changer,” Sullivan said. “Figuring out the genetic basis of major depression has been really hard. A huge number of researchers across the world collaborated to make this paper, and we now have a deeper look than ever before into the basis of this awful and impairing human malady. With more work, we should be able to develop tools important for treatment and even prevention of major depression.”

Read the full article here.

How We’ve Tackled the Evolving Science of DNA

“No article we have ever published has been more difficult” than our first feature about the molecule of life, which appeared 42 years ago.”

On April 25, 1953, the journal Nature published a picture that sparked a revolution: the first drawing of the structure of the DNA molecule. That landmark discovery, made possible by the x-ray crystallography work of Rosalind Franklin and Maurice Wilkins, put Francis Crick and James Watson at the forefront of the burgeoning field of molecular biology. Within weeks, the New York Times proclaimed that the discovery “should make biochemical history,” and in the years since, news outlets have published reams about DNA and its importance to unraveling the way life works.

But for its part, National Geographic didn’t make the plunge into molecular biology until 23 years after the discovery of the double helix. For a magazine that had long prided itself on place-driven narratives and photography, grappling with the microscopic world of “the new biology” pushed National Geographic staff at the time to the point of discomfort. It took the magazine more than two years to assemble its first foray into molecular biology, a splashy feature titled “The Awesome Worlds Within a Cell” that ran in the September 1976 issue. Rereading the story today, the relieved sigh the staff must have made as the story went to press is almost palpable. “No article we have ever published has been more difficult, either in the amount of effort and skill that went into its preparation, or in the perseverance readers must bring to it if they are to understand this complex new face of science,” Gil Grosvenor, then National Geographic’s editor-in-chief, wrote in an accompanying letter to readers.

Read the full article here.

Why Americans Still Avoid Msg, Even Though Its ‘Health Effects’ Have Been Debunked

On April 4, 1968, a biomedical researcher wrote a letter that would forever change how America eats. In it, Robert Ho Man Kwok described a strange illness he contracted at Chinese restaurants — specifically those that cooked with the flavoring MSG. MSG was popular in the United States at the time. But when Kwok’s letter hit the New England Journal of Medicine, the ingredient’s fortunes reversed: Consumers spurned it. Food-makers axed it. Scientists threw themselves into critical MSG research. Fifty years later, 4 in 10 U.S. consumers still say they actively avoid MSG, according to the International Food Information Council, an industry-funded nonprofit that advocates for science in nutrition. That’s despite repeat studies that have shown MSG does not produce numbness, weakness or heart palpitations, the symptoms Kwok experienced.

“Sometimes it’s easier to put a ‘free from X’ label on something than to actually educate consumers about it,” said Lisa Watson, the spokeswoman for the Glutamate Association, an MSG trade group. “Personally I wish food companies would take the longer view.” In an effort to push back, Watson and her member companies regularly meet with chefs and nutritionists to talk up the merits of MSG. She has been heartened by statistics that show younger consumers are not quite as adverse to the product as their parents were. She has been glad to see media outlets run debunks of the MSG myth, and celebrity chefs, such as Hugh Acheson and David Chang, vocally embrace the seasoning. The “foodie movement” also has revived interest in cooking that shows off science, said Sarah Tracy, an adjunct professor at UCLA’s Institute for Society and Genetics who will publish a history of MSG this year. While Tracy isn’t entirely willing to give the seasoning her seal of approval — it is being researched for its possible role in promoting weight gain, she points out — she sees other cooks and consumers embracing the seasoning as a sign of their culinary savviness.

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Food for Thought: Was Cooking a Pivotal Step in Human Evolution?

Fireplace, Wood, Fire, Boil Water, Cook, Flame, HeatThe shift to a cooked-food diet was a decisive point in human history. The main topic of debate is when, exactly, this change occurred. All known human societies eat cooked foods, and biologists generally agree cooking could have had major effects on how the human body evolved. For example, cooked foods tend to be softer than raw ones, so humans can eat them with smaller teeth and weaker jaws. Cooking also increases the energy they can get from the food they eat. Starchy potatoes and other tubers, eaten by people across the world, are barely digestible when raw. Moreover, when humans try to eat more like chimpanzees and other primates, we cannot extract enough calories to live healthily. Such evidence suggests modern humans are biologically dependent on cooking. But at what point in our evolutionary history was this strange new practice adopted? Some researchers think cooking is a relatively recent innovation—at most 500,000 years old. Cooking requires control of fire, and there is not much archaeological evidence for hearths and purposefully built fires before this time.

Like all ideas about human evolution, the cooking hypothesis can only be tested indirectly—without a time machine we cannot know exactly what happened in our evolutionary history. But there are several converging pieces of evidence that support Wrangham’s cooking hypothesis.

Read the full article here.

What Happens When You Put Evolution on Replay?

A team of scientists from the University of Arizona have engineered an instant replay switch for evolution. The technique, known as ancestral gene resurrection, inserts ancient genes into modern E. coli bacteria. It gives researchers the opportunity to watch evolution unfold again and again, providing insights into how life evolved on early Earth, and what it might potentially look like on other planets. “Organisms can function just fine even when they’ve been engineered with an essential gene that is over 700 million years old,” the study’s lead author Betül Kaçar, an astrobiologist at the University of Arizona, tells Astrobiology Magazine. “This work is a proof of concept. The next questions are: How far back can we go? And would we expect the sequences to evolve and function the same way that they did? Just because sequences are similar doesn’t mean that the gene will function in the same way.”

Kaçar and colleagues published their work in the Journal of Molecular Evolution.

Read the full article here.

Complete Genomes of Extinct and Living Elephants Sequenced

Image result for elephantAn international team of researchers has produced one of the most comprehensive evolutionary pictures to date by looking at one of the world’s most iconic animal families — namely elephants, and their relatives mammoths and mastodons-spanning millions of years. The team of scientists-which included researchers from McMaster, the Broad Institute of MIT and Harvard, Harvard Medical School, Uppsala University, and the University of Potsdam-meticulously sequenced 14 genomes from several species: both living and extinct species from Asia and Africa, two American mastodons, a 120,000-year-old straight-tusked elephant, and a Columbian mammoth. The study, published in the Proceedings of the National Academy of Science, sheds light on what scientists call a very complicated history, characterized by widespread interbreeding. They caution, however, the behaviour has virtually stopped among living elephants, adding to growing fears about the future of the few species that remain on earth.

Read the full article here.

Monkey Vocabulary Decoded

Image result for marmosetsFrom short ‘tsiks’ and ‘ekks’ to drawn-out ‘phees’ — all the sounds produced by marmoset monkeys are made up of individual syllables of fixed length: that is the result of a study by a team of researchers headed by Dr. Steffen Hage of the Werner Reichardt Centre for Integrative Neuro-science (CIN) at the University of Tübingen. The smallest units of vocalization and their rhythmic production in the brain of our relatives could also have been a prerequisite of human speech. The study was just published in Current Biology.

The researchers recorded thousands of instances of the little monkeys’ ‘tsiks’, ‘ekks’ and ‘phees’ in a sound chamber. They interrupted the animals’ natural vocalization with white noise at irregular intervals. The researchers effectively ‘talked over’ the monkeys, causing them to fall quiet. Such a rhythm might be an evolutionary prerequisite on the path to developing true speech. The new study demonstrates that research in marmosets can provide the necessary clues to better understand the origins and properties of human speech — a question that has been much debated in the scientific community.

Read the full article here.