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Two progressively degenerative diseases, amyotrophic lateral sclerosis (ALS, commonly known as Lou Gehrig’s disease) and frontotemporal dementia (FTD, recently in the news with the diagnoses of actor Bruce Willis and talk show host Wendy Williams), are linked by more than the fact that they both damage nerve cells critical to normal functioning—the former affecting nerves in the brain and spinal cord leading to loss of movement, the latter eroding the brain regions controlling personality, behavior and language.

Research studies have repeatedly shown that in patients with ALS or FTD, the function of TAR DNA-binding protein 43, more commonly called TDP-43, becomes corrupted. When this happens, pieces of the genetic material called ribonucleic acid (RNA) can no longer be properly spliced together to form the coded instructions needed to direct the manufacture of other proteins required for healthy nerve growth and function.

The RNA strands become riddled with erroneous code sequences called “cryptic exons” that instead affect proteins believed to be associated with increased risk for ALS and FTD development.

When a long-term memory forms, some brain cells experience a rush of electrical activity so strong that it snaps their DNA. Then, an inflammatory response kicks in, repairing this damage and helping to cement the memory, a study in mice shows. The findings, published on 27 March in Nature1, are “extremely exciting”, says Li-Huei Tsai, a neurobiologist at the Massachusetts Institute of Technology in Cambridge who was not involved in the work. They contribute to the picture that forming memories is a “risky business”, she says. Normally, breaks in both strands of the double helix DNA molecule are associated with diseases including cancer. But in this case, the DNA damage-and-repair cycle offers one explanation for how memories might form and last.

It also suggests a tantalizing possibility: this cycle might be faulty in people with neurodegenerative diseases such as Alzheimer’s, causing a build-up of errors in a neuron’s DNA, says study co-author Jelena Radulovic, a neuroscientist at the Albert Einstein College of Medicine in New York City.

Salk scientists unveil RNA capabilities that enable Darwinian evolution at a molecular scale, and bring researchers closer to producing autonomous RNA life in the laboratory.

Charles Darwin described evolution as “descent with modification.” Genetic information in the form of DNA sequences is copied and passed down from one generation to the next. But this process must also be somewhat flexible, allowing slight variations of genes to arise over time and introduce new traits into the population.

But how did all of this begin? In the origins of life, long before cells and proteins and DNA, could a similar sort of evolution have taken place on a simpler scale? Scientists in the 1960s, including Salk Fellow Leslie Orgel, proposed that life began with the “RNA World,” a hypothetical era in which small, stringy RNA molecules ruled the early Earth and established the dynamics of Darwinian evolution.

If you had to estimate the number of people in a room, without counting them one-by-one, by nature you would overcount them. That’s because, simply put from a Darwinian perspective of how we have evolved, it’s better to overcount potentially harmful agents and predators than to underestimate them.

This overcounting social behaviour is shown to be true in humans as well as animals. It’s certainly better to detect too many tigers (even if absent) during a jungle excursion than to miss a hungry one!

Now, EPFL neuroscientists show that if you experience hallucinations, especially when related to an illness like Parkinson’s disease, then you will overestimate the number of people in a room to a greater degree. They also show that if you have hallucinations but are asked to estimate the number of boxes in a room, which are inanimate control objects, then no extra over-estimation occurs, shedding light on the social nature of this overcounting. The results are published in Nature Communications.

Scientists created a highly accurate reference genome for one of the most important modern crops and found a rare example of how genes confer disease resistance in plants. Exploring sugarcane’s genetic code could help researchers develop more resilient and productive crops, with implications for both sugar production and biofuels.