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

August 12, 2021

Chameleon robots change colors as they crawl

Aiming to develop next-generation wearable camouflage, researchers at Seoul National University have created a robotic chameleon that changes colors in real time as it crawls. The robot itself is a soft-body, salamander-like slitherer, similar to what we have seen before, but its skin is the real technological breakthrough. Its top side is covered in a layer of thermochromic liquid crystals connected through a stack of patterned silver nanowires to a feedback control system that reads color sensors on its belly. What does that all mean? Simply put, the robot inputs the tints and tones of the ground it covers and modifies its skin color accordingly in real time. So cool. Nature Communications

A chameleon robot that changes its skin color according to the background as it moves. Seung Hwan Ko/Seoul National University

Anti-sperm antibodies: Hormone-free birth control?

Many women seeking birth control cannot tolerate contraceptives like the pill, which despite being cheap, easy, and effective, relies on exogenous hormones with side effects. Now scientists at the University of North Carolina at Chapel Hill have engineered a non-hormonal barrier method to prevent pregnancy based on antibodies found naturally in some women that bind to sperm. Taking fragments of these existing antibodies, they developed a more potent monoclonal form and tested it in sheep, showing it slowed sperm motility by 99.9 percent. Though they don’t yet know how effective it will be at preventing pregnancies, they are developing an antibody-containing intravaginal ring to explore just that. Science Translational Medicine

Urbanization and mental health: Will larger cities make us happier?

With more than half the world’s population now living in or around cities, a demographic trend projected to continue to increase this century, there is some urgency to understand the environmental, economic, and human health impacts of greater numbers of people living closer together in the future. Urbanization is already linked to increasing levels of mental stress, but in a surprising result, a group of researchers at the University of Chicago predicts that larger U.S. cities will provide a buffer against depression in the future. Based on mathematical modeling, their work predicts lower depression rates in larger cities and suggests the effect is due to the fact that the greater number of social interactions in urban environments, even casual ones, provide a buffer against negative affect in people who are otherwise vulnerable to depression. PNAS

First there was young blood—now young poop?

Could the gut microbiome be a therapeutic target to increase lifespans or healthspans? That’s the implication of a new study by researchers at University College Cork in Ireland. They gave old mice fecal transplants taken from either young or old mice and showed that those taken from the young mice reversed age-associated brain and peripheral immune senescence and altered hippocampal metabolome and transcriptomes in the recipient old mice. The young mouse donor microbiota also dulled age-associated impairments in cognitive behavior, the researchers report. Nature Aging

A worm in the phenotype gap

For geneticists bent on uncovering the secrets of animal physiology and disease, DNA sequences are not enough. They also need to understand how genotypes translate into the characteristic phenotypes we see in mature organisms: distinct cells, specialized tissues, specific behaviors, morphological appearances, and underlying mechanisms. To bridge this gap, a European collaboration led by the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, and the Friedrich Miescher Institute for Biomedical Research in Basel, Switzerland, has developed a framework for integrating gene expression data with cellular morphological information for an entire organism by combining genomic data of the nereid worm Platynereis dumerilii with whole-body, high-resolution electron microscopy. Cell

Fasting protects mice against food-borne illness

People, mice, monkeys, and many other animals tend to lose their appetites when they are sick, and the cross-species ubiquity of this effect has led scientists to hypothesize that fasting while sick may be some form of self-protective behavior we innately fall into. While some studies have supported this hypothesis, it has never been tested directly until now. A group of researchers at the University of British Columbia in Vancouver, Canada, fed fasting mice food laced with Salmonella enterica bacteria and found they were protected from infection and prevented the bacteria from colonizing the gut. Fasting mice were not protected from injections of the same bacteria, however, which highlights the central role of the microbiome in this protection. PLOS Pathogens

Better, faster, cheaper RNA—with a little salt

Researchers at the University of Massachusetts Amherst have developed a new process for making RNA for therapeutic applications that promises to generate it at higher purity, in larger amounts, and at lower cost than any previous process could manage. Their setup involves attaching a molecule known as a “T7 RNA polymerase” to a magnetic bead. That keeps the RNA-producing enzyme tethered close to a DNA template, which it can read—a specific sequence that codes for a specific RNA. Increasing the salinity of the solution, the researchers found, inhibits the growth of impurities by more than ten times over existing methods. Clearly, RNA drugs, including mRNA vaccines, will feature prominently in our future, so this is an important step in increasing safety and streamlining costs. Journal of Biological Chemistry