The evidence that daily patterns of physiology and behaviour in mammals are governed by circadian ˜clocks' is based almost entirely on studies of nocturnal rodents. This Essay proposes that the nocturnal rodent/human paradigm of circadian rhythms is unhelpful when considering the broader manifestation of temporal organisation of activity in mammals.
As the field of extracellular vesicles rapidly expands, many questions remain unanswered; this Unsolved Mystery article provides a systematic compilation of these challenges, and formulates a path to addressing them.
This Community Page article presents the Human Brain Project; a European Flagship project with a ten-year horizon aiming to understand the human brain and translate neuroscience knowledge into medicine and technology.
This Community Page article describes evidence-based changes to the design of a large-enrolment introductory biology course at a regional comprehensive university; exam scores increased and failure rates decreased for all students, with under-represented minority students'predominantly African-Americans'benefiting disproportionately.
By coupling single-board computers with increasingly available, inexpensive sensors and cameras, it is possible to construct custom, low-cost animal habitats that monitor undisturbed activity and physiological parameters with real-time resolution.
During development, sensory hair cells undergo a series of critical maturation steps that are sequential and presumed coupled, but whether regenerated hair cells mature similarly is unknown. This study shows that regenerated vestibular hair cells acquired some mature somatic features, but the apical bundles remained immature.
Type III secretion machines evolved to inject bacterial effector proteins into eukaryotic cells, becoming active upon bacterial contact with the target cells. This study provides insight into the mechanism by which the contact signal is transduced to activate the protein secretion machine.
Behavioral experiments with the spider Agelena labyrinthica, coupled to computational modelling, show that an increase in mobility with age drives dispersal in gregarious spiderlings of a solitary species and that the subsequent social isolation triggers aggression.
The expression of a sparse subset of human genes forms two opposed gradients that capture the processing hierarchy of visual cortex; these transcription gradients emerge at different points during human development and distinguish human from nonhuman primates.
A global view of the Hsp90 chaperone interactome in the fungal pathogen Candida albicans reveals the dynamic role of Hsp90 in response to environmental perturbations, and highlights a novel connection between Hsp90 and the regulation of mRNA-associated protein granules.
Male sea lampreys release via their ejaculates a highly specific and stimulatory sex pheromone, spermine, that activates a trace amine-associated receptor in the olfactory epithelium and attracts ready-to-mate females.
A naturally occurring bacterial toxin inspired the design of novel cyclic heptapseudopeptide antibiotics with limited resistance; these new peptidomimetics are active against gram-negative and -positive multi-resistant ESKAPE pathogens.
Reversible deactivation of the dorsal anterior cingulate cortex ' an area of the cognitive control network ' impairs rule maintenance but not rule switching per se, and disrupts task-related oscillatory activities in the dorsolateral prefrontal cortex ' another area of the same network.
An auxin-regulated calcium-dependent signal transducer, CMI1, regulates auxin responses and root development, providing a basis for cross talk between auxin and calcium signaling in plants.
Our understanding of marine fish larva dispersal is currently limited by sparse data and unvalidated models; combining DNA parentage matches with an oceanographic model of fish larvae on Australia's Great Barrier Reef allows the authors to ground-truth a vital tool for sustainably managing coral reef fisheries.
After treatment with drugs that target apicoplast functions, malaria parasites are initially superficially healthy and go on to infect new erythrocytes. This cell biology study shows that the parasites subsequently die in their second cycle due to trafficking defects caused by depletion of prenyl groups.
Comparative genomics and phylogenetic analysis show how a handful of key components have given rise to a profusion of apparatuses involved in important bacterial and archaeal cellular processes (motility, adhesion, protein secretion, and DNA uptake).
Human papillomaviruses cause various diseases associated with cellular hyperproliferation, including cervical cancer. Structural, biochemical, and cellular analyses reveal the molecular basis and significance of the intermolecular interaction between the E7 protein of human papillomavirus 18 and the human tumor suppressor protein PTPN14.
The Hippo pathway kinases Lats1 and Lats2 constrain Yap1/Taz and NFkappaB, allowing pancreatic progenitor differentiation during embryonic development. In the absence of Lats1/2, hyperactive YAP1/TAZ and NFkappaB hijack pancreatic progenitor cell fate, resulting in partial epithelial-to-mesenchymal transition, an initial step in tumorigenesis.
By using monkeyflower genome sequences to reconstruct patterns of evolution over one million years of divergence, this study shows that natural selection plays a key role in driving genetic differentiation between emerging species.
There are two competing explanations for electrophysiological signatures during cognitive processes. One assumes simultaneous increases in high frequencies paired with decreases in low frequencies, whereas the other suggests that different frequencies index separate oscillatory processes. This study reports data that support the latter view.
The efficient coding hypothesis suggests that sensory processing adapts to the stimulus statistics to maximize information while minimizing energetic costs. This study finds that an auditory spatial processing circuit distributes activity across neurons to enhance processing efficiency, focally improving spatial resolution both in neurons and in human listeners.
How do cells switch between selective and non-selective autophagy? This study shows that yeast Atg11 is a key coordinator of selective autophagy, binding and tethering donor vesicles to initiate the formation of selective autophagosomes. On induction of non-selective autophagy, Atg11 is outcompeted by its counterpart Atg17, which nucleates autophagosomes independently of cargo.
Introducing human disease-associated mutations in the membrane skeletal protein spectrin into the nematode Caenorhabditis elegans reveals that spectrin mutations down-regulate ciliary gene expression, affect intraflagellar transport, disrupt axonemal microtubule organization, and inhibit ciliogenesis.
Fibroblasts in secondary lymphoid organs can be active participants in adaptive immunity, often enhancing T-cell responses. This study shows how these fibroblasts dampen T-cell responses via the constitutive production of the COX2-dependent prostaglandin PGE2, including during persistent viral infection.
Disassembly of the primary cilium is required for cell cycle progression. Live cell imaging reveals that this process involves a tunable decision between gradual resorption and rapid deciliation; in IMCD3 mammalian kidney cells, the predominant behavior is deciliation.
Most animals possess specialized excretory organs to deposit toxic waste products from their body; others are assumed to use passive diffusion via the skin. However, investigation of one cnidarian and two acoelomorph species, which do not possess excretory organs, shows that the gut tissue is the most active excretory site and that acoelomorphs use active transport.
Ancient DNA is known to survive in cold environments for tens of millennia, but it is assumed that ancient RNA could not persist in such a way due to its relative instability. However, this study shows that under permafrost conditions, ancient RNA can survive well enough to show tissue specificity even in mammalian soft tissues.
Methods and Resources
Androgenetic haploid embryonic stem cells expressing Cas9 and a medium-scale sgRNA library provide a means to mutate genes at the organism level, enabling knockout-based screening in mammalian systems. Applying this approach successfully identified Irx5 as a regulator of bone development.
Single-cell RNA sequencing allows dissection of the transcriptomic landscape of the human fetal neural retina (NR) and retinal pigment epithelium (RPE), revealing a tightly regulated spatiotemporal gene expression network of human retinal cells, as well as dynamic and functional interactions between the NR and RPE.
This study describes a "plug-and-play" synthetic biology platform for producing variants of type II polyketides in Escherichia coli, opening the door for high-throughput discovery of antimicrobials and other active pharmaceutical ingredients.
ATG8 is a ubiquitin-like protein involved in autophagy pathways. Biochemical characterization of the expanded ATG8 gene family in plants revealed an additional layer of specificity in selective autophagy, determined by ATG8's N-terminal ÃŸ-strand.