editors’ picks

People who live with cats attribute a lot of calculating behaviors to them. If this includes thinking your cat has a fundamental grasp of cause and effect, then you’re backed up by recent research by Saho Takagi and colleagues at Kyoto University.

Polymorphic animals are those that have distinctly different outward traits, such as a color, within a species. Black sparrowhawks (Accipiter melanoleucus)), despite their common name, exist in a version with a white front as well as an all-dark version. But why would evolution simultaneously favor such contrasting color variations within the species?

A recent study published in Molecular Biology and Evolution describes a phenomenon where populations that have typically consumed vegetarian diets over hundreds of generations have evolved a “vegetarian gene”.

If you rouse a sleeping dragon, you might be interrupting its dreams. Or at least that’s the suggestion from recent studies at the Max Planck Institute for Brain Research. A team led by Gilles Laurent set out to learn how the Australian dragon (Pogona vitticeps) responds to visual information, but continuous monitoring of brain activity with electrodes revealed other intriguing data. When sleeping, the reptiles’ brains emitted alternating patterns that resembled the switching between slow-wave deep sleep and rapid eye movement (REM) observed in birds and mammals, including humans. The alternation in reptile brains was quicker and more regular than in birds and mammals, but otherwise comparable. The team made additional observations that bolstered their suspicion that the lizards were experiencing REM, and they discovered additional similarities to mammal and bird sleep, such as coordination between regions of the brain.

New research suggests that ravens understand that others have minds. Theory of mind, the ability to attribute perceptions and mental states to others, either like or different from one’s own, has previously been assumed to be the domain of humans only.

A study recently published in the Proceedings of the National Academy of Sciences furthers our understanding of tumors and the source of the mutations that are found within their DNA. This study, carried out by researchers at Wayne State University and Indiana University, highlights a new mutation signature found in cancer cells that is caused by members of the APOBEC3 family of proteins.

A single enzyme, ribonucleotide reductase (RNR), is responsible for making all four deoxyribonucleotides (dNTPs) and ensuring that they are present at the ratios required to synthesize new DNA. This is possible because RNRs change their substrate specificity in response to dNTP abundance. For example, when dGTP is abundant it binds RNR, increase its affinity for ADP, and thus shifts synthesis to dATP. Scientists in the Drennan lab at the Massachusetts Institute of Technology have long been fascinated by this unusual enzyme and now describe the allosteric changes that underlie RNR’s ability to shift specificity and maintain the proper dNTP pool in our cells.

Imagine you’re singing the Batman theme song in a large chorus and you need to identify your own voice in the playback. Sounds difficult, but it is similar to what individual bats in colonies must do to navigate and find tiny morsels of food such as insects via echolocation. New research from a team at Tel Aviv University led by Yossi Yovel indicates they do this by modifying the volume and duration of the calls and then following the echo that exactly matches. If you did this in your chorus, you’d pick out your own voice by knowing whether you were singing “batman,” “batmaan,” or “batmaaan.” The finding dispels the previous assumption that the bats were modifying the pitch of their voices.

A single enzyme, ribonucleotide reductase (RNR), is responsible for making all four deoxyribonucleotides (dNTPs) and ensuring that they are present at the ratios required to synthesize new DNA. This is possible because RNRs change their substrate specificity in response to dNTP abundance. For example, when dGTP is abundant it binds RNR, increase its affinity for ADP, and thus shifts synthesis to dATP. Scientists in the Drennan lab at the Massachusetts Institute of Technology have long been fascinated by this unusual enzyme and now describe the allosteric changes that underlie RNR’s ability to shift specificity and maintain the proper dNTP pool in our cells.

Researchers at Albert Einstein College of Medicine and the US Army Medical Research Institute of Infectious Diseases have discovered a potential immunotherapeutic treatment for two of the deadliest Ebola virus strains.