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Dubilier is hardly alone in her plight. A heaping teaspoon of soil or a shot of ocean water may contain as many as one million bacterial species. Many of them are potential gold mines of chemicals and metabolites with medicinal, engineering, and energy applications. But when researchers have tried to culture these microbes in the lab, only a minority of cells form colonies. Clearly, nutrients, a carbon source, and time are usually not enough to coax bacteria isolated from the wild to grow in a laboratory setting. So what's the missing ingredient?

Six years ago, Yale University's Stephen Stearns and colleagues took advantage of a long-running study in Framingham, Massachusetts, to assess whether the effects of natural selection could be discerned among the people in the multigenerational study population. Over the last seven decades, public-health researchers have been monitoring the residents of Framingham, noting their vital statistics as well as blood sugar and cholesterol levels to understand the factors that lead to heart disease. As the initial group of research subjects got older, the study started to include their children, and then their grandchildren. The records provide a unique view of the health of a segment of the American population since 1948.

Plant species belonging to divergent branches of the evolutionary tree are known to have independently evolved caffeine production. According to scientists at Western Michigan University, caffeine-producing plants have taken a number of different biochemical routes to synthesize the stimulant. Coffee, tea, cocoa, orange, and guaraná plants make caffeine using an array of enzymes and substrates, the researchers reported in PNAS this week (September 20).

It took about 9,000 years and alterations in six genetic pathways to transform the inedible grass teosinte (left) into the corn we eat today (right). (Center: a first generation hybrid between teosinte and corn)

Researchers at the University of Pennsylvania performed "stress tests" on pregnant mice using a predator's odor, restraint, or unfamiliar noises. After the mice gave birth, the scientists analyzed the bacterial communities in their vaginas and in their pups' colons. The researchers found that stress during pregnancy altered the expression levels of several proteins involved in vaginal immunity and the frequency of Lactobacillus bacteria, which, expectedly, correlated to lower frequencies of Lactobacillus within their pups' gut microbiomes. Male pups of stressed mothers also displayed an increase in anaerobic bacteria like Clostridium and Bacteroidesin.

In our view, and that of organizations such as the American Society of Clinical Oncology, the World Cancer Research Fund International, and the American Cancer Society, obesity-related cancers will arguably be the most urgent issue in the cancer field in the next decade.

Some 20 percent of cancer-related deaths in the U.S. can be attributed to obesity, making it the number-one preventable cause of cancer death in the country. But with myriad metabolic and inflammatory changes associated with obesity, determining the mechanisms that underlie the obesity-cancer link has proven challenging.

Stress is implicated in increased tumor progression risk and poor survival in cancer patients. A number of recent studies have linked these effects to the promotion of tumor cell dissemination through the bloodstream via stress-induced pathways. Now, a mouse study led by researchers in Australia has revealed the mechanisms by which stress modulates cancer's spread through another transport network open to tumor cells-the lymphatic system.

"Millions of people who suffer from less-intense sleep problems do suffer myriad health burdens. In addition to emotional distress and cognitive impairments, these can include high blood pressure, obesity, and metabolic syndrome. And recent research has suggested even mild sleep loss, the kind people often subject themselves to during the work week by watching late-night TV until midnight then rising before dawn, may lead to metabolic, cardiovascular, cognitive, and neurologic dysfunction."

At least 140 alternative RNA nucleotide forms exist. On mRNA, the most common is the methylation of adenosine on the N6 position (m6A).

Quintana-Murci and his colleagues also took advantage of a previously published map of areas of the human genome where Neanderthal genes are present, showing that innate immune genes are generally more likely to have been borrowed from Neanderthals than genes coding other types of proteins. Specifically, they noted that 126 innate immune genes in present-day Europeans, Asians, or both groups were among the top 5 percent of genes in the genome of each population most likely to have originated in Neanderthals. The cluster of toll-like receptor genes, encoding TLR 1, TLR 6, and TLR 10, both showed signs of having been borrowed from Neanderthals and having picked up adaptive mutations at various points in history. Meanwhile, a group led by Janet Kelso of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, used both the same previously published Neanderthal introgression map that Quintana-Murci used and a second introgression map. The researchers searched for borrowed regions of the genome that were especially long and common in present-day humans, eventually zeroing in TLR6, TLR10, and TLR1. These receptors, which detect conserved microbial proteins such as flagellin, are all encoded along the same segment of DNA on chromosome four.

In the 1950s, Idaho sheep ranchers had a problem. About a quarter of their lambs were being born dead or deformed-sometimes with a single eye centered in the middle of their forehead, like the Cyclops of Greek legend, or missing their upper jaw. There were times when the pregnant ewes couldn't give birth at all, carrying the mutated fetuses until they were surgically delivered or the ewes themselves died. Unbeknownst to the farmers, the cause was a poisonous plant, western false hellebore (Veratrum californicum). Eventually, the plant would inspire a successful cancer therapy-but at the time, the sheep were what mattered.

When it's completely unraveled, DNA is known to extend approximately six feet in length, yet is somehow able to cram itself into a cell's nucleus. In a study published today (July 27) in Science, researchers created a novel visualization method that revealed a 3-D glimpse of chromatin as it sits jam-packed within the nuclei of human cells. The researchers found that, contrary to how it's depicted in most textbooks, chromatin does not fold in on itself in an organized manner to create distinct structures. Instead, it forms a pliable, inconsistent chain characterized by a wide variety of folding patterns. 

Like humans, some golden retrievers develop Duchenne muscular dystrophy (DMD), a hereditary muscle wasting condition that begins early in life. Using gene therapy, scientists were able to restore muscle function in dogs with the disease, according to a study published today (July 25) in Nature Communications.

Following on the achievements of Chinese researchers, scientists in the United States have used CRISPR to manipulate the genomes of viable human embryos, MIT Technology Review reported yesterday (July 26). The work, not yet published, reportedly corrected defective genes from sperm donors in dozens of embryos, which were allowed to grow for several days.

In the study, published Monday (May 1) in Nature Biotechnology,  Luo and colleagues set their sights on two fusions genes they had previously found to be associated with prostate cancer and various forms of rapid and invasive cancer, including liver tumors. Using a modified CRISPR-Cas9 tool that creates a single- rather than double-stranded break in DNA, they targeted the chromosomal breakpoints that form these fusion genes and replaced fusion DNA with a gene encoding the enzyme HSV1-tk. This enzyme effectively kills tumor cells by converting the drug ganciclovir into its active form, which then blocks DNA synthesis and leads to cell death. (Ganciclovir is used to treat cytomegalovirus in humans.)