The week’s most astounding developments from the neobiological frontier.

June 3, 2021

Real-time movies of molecules in motion

Researchers in the Netherlands and Germany have produced movies of molecular simulations to help understand a type of dynamic DNA–protein interaction that controls gene expression. DNA in human cells is kept neatly organized and ready for gene expression by packing it efficiently into chromatin structures, where it’s twisted around proteins known as histones. Those histones open and close to allow other enzymes to access the DNA as needed, and this process is modified by methylation of those same histone proteins, an important epigenetic means of regulating gene expression in the body—and one that has been implicated in aging. PLOS Computational Biology 

One-and-done cure for sickle cell works in mice

About 1 in 13 Black Americans are born with a genetic sickle cell trait—a slight variation in one of the two copies of their genes coding for hemoglobin proteins, which are found in red blood cells and help ferry oxygen to tissues. People with one copy of a sickle cell trait have no symptoms, but when any two of them have children, their kids have a 25 percent chance of inheriting both genes. That leaves them predisposed for sickle cell disease, a painful and sometimes deadly illness that causes their cells to misshape and occlude blood vessels. Scientists at the Broad Institute of Harvard and MIT have developed a way to edit specific DNA bases in human blood stem cell precursors to eliminate the sickle cell trait. In a set of mouse experiments published this week, they showed that they could transplant these modified cells into mice, where they successfully reproduced, differentiated into normal, non-sickled red blood cells, and rescued mice from sickle cell symptoms. Nature

Universal vaccines for influenza moving forward

Designing vaccines against influenza is tricky because the virus naturally mutates over time, making vaccines less effective, which is why new seasonal flu shots are administered every year. Influenza is also capable of making more radical evolutionary jumps because of its unusual segmented genome, which allows separate viruses to swap large cassettes of DNA, possibly recombining them into the next super strain, like the ones that caused deadly pandemics in 1918, 1957, and 1968. This week the National Institute of Allergy and Infectious Diseases launched a phase 1 clinical trial of its experimental FluMos-v1 vaccine, which is designed to induce long-lasting protection against many different strains, even newly emerging ones. In separate work, a group at the University of Chicago and The Scripps Research Institute have studied one type of broadly neutralizing antibody that provides broad protection against H1N1 influenza strains spanning 40 years of viral evolution, which they say suggests a framework for next-generation vaccines. Science Translational Medicine

Overconfidence is crucial factor in spread of misinformation

Misinformation is easy to define as an abstract concept but often hard to spot in actual fact—almost the exact opposite of former Supreme Court Justice Potter Stewart’s definition of pornography: I know it when I see it. Most Americans, in fact, don’t see misinformation at all, and in surveys claim to have neither ever seen nor shared it. But while those people may never knowingly share falsehoods, they could be doing so unwittingly. Part of the problem, according to a new study, is overconfidence in one’s own news judgment. Looking at two large, nationally representative surveys involving 8,285 Americans, the study found most people overestimate their ability to spot fake news. It found that overconfident people are more likely to visit untrustworthy websites, often fail to distinguish between true and false claims about current events, and are more likely to share false content on social media—especially if it fits their political worldview. PNAS

New device for photoacoustic CT imaging of the human brain

A novel approach for functional human brain imaging was described this week by researchers at Caltech and USC. Similar to how fMRI images blood flow in the brain as a proxy for neuronal activity, the new approach quantifies oxygen saturation and blood hemoglobin in the brain—but with light and sound, using photoacoustic computed tomography. This technique has traditionally failed to provide the necessary resolution, but the new device employs massively parallel ultrasonic transducers arranged in a hemisphere around a person’s head to produce 10-centimeter wide image slices with 350-micron and 2-second resolution, which the researchers say should allow for faster detection of functional activation in the brain. Nature Biomedical Engineering

Artificial finger has feelings too

How you feel fine textures with your fingers is a complicated process involving physical stimuli triggering mechanically sensitive protein channels under the skin, which send nerve signals to the brain where they are integrated into the experience of touch—a process so complicated nobody has ever been able to add that basic sensory ability to a robotic hand or human prosthesis. But an artificial finger now has the ability, thanks to a new artificial neural tactile skin system fashioned from polymer composite sensors and electronic signal converters at Sungkyunkwan University in South Korea. The sensors could generate signals to stimulate motor nerve firing and leg muscle contraction in rats. Nature Electronics

Melts in your mouth, not in the lab

While it’s not yet a month since we last wrote about chocolate, we just read a study we have to share. The tempering, conching, and molding part of the chocolate-making process involves careful manipulations to tease the fat in the chocolate into optimal molecular crystal forms so that it is glossy, snaps crisply, and melts just so. Now researchers at Osaka University and the Japanese food company Nisshin OilliO have developed a new way to study fat crystals in chocolate and discovered that the side of a bar that touches the mold into which it’s poured has a more orderly crystal structure than the side facing the air, which they say may help produce better chocolate—and we thought you should know. Crystal Growth & Design