The National Museum of Natural History announced this summer that it has reached a 50-year loan agreement with the U.S. Army Corps of Engineers to […]

The post T. rex to rule Dinosaur Hall in Washington, D.C. appeared first on Smithsonian Insider.

In June, Odile Madden, materials scientist at the Smithsonian’s Museum Conservation Institute, was a participant on a 6-day interdisciplinary expedition to a number of beaches […]

The post Q&A: Plastics expert Odile Madden on plastic debris in Alaskan waters appeared first on Smithsonian Insider.

The giant panda cub born at the Smithsonian’s National Zoo Aug. 23 received her first veterinary exam late yesterday afternoon and was given a clean […]

The post Panda cub receives first exam appeared first on Smithsonian Insider.

  This image is a close-up of the skull of the Tyrannosaurus rex skeleton known as the Wankel T. rex which was installed in front […]

The post T-rex to rule Dinosaur Hall appeared first on Smithsonian Insider.

On April 15 the National Museum of Natural History took delivery of a nearly complete Tyrannosaurus rex skeleton. Called the Nation’s T. rex, it will be the centerpiece of […]

The post Smithsonian Welcomes “Nation’s T. rex” to Washington, D.C. appeared first on Smithsonian Insider.

A newly released study focusing on an extinct species, the Caribbean monk seal (Monachus tropicalis), has revealed just how evolutionarily unique its only two living […]

The post Too valuable to lose: Extinct relative reveals rarity of last two remaining monk seal species appeared first on Smithsonian Insider.

After eluding scientists for nearly 80 years, the Clarion nightsnake (Hypsiglena ochrorhyncha unaocularus), a nocturnal reptilian species that was initially discovered in the first half […]

The post Lost species of nightsnake rediscovered in Mexico appeared first on Smithsonian Insider.

It is related to one of the world’s most destructive invasive species, and possibly the slimiest. Thirty-five pounds of live giant West African snails (Archachatina […]

The post Slimy invaders, giant snails: Q&A with mollusk expert Ellen Strong appeared first on Smithsonian Insider.

Astronomers have discovered a transiting exoplanet with the longest known year. Kepler-421b circles its star once every 704 days. In comparison, Mars orbits our Sun […]

The post Transiting exoplanet with longest known year appeared first on Smithsonian Insider.

When some of the world’s largest mammals come your way, most animals steer clear. Not the genet. The small cat-like carnivore was captured on film […]

The post Maybe it’s safer riding a rhino. Genet expert poses new ideas on the mammal’s hitchhiking behavior appeared first on Smithsonian Insider.

Unless you live under a lunar rock, you’ve probably heard about or seen director Christopher Nolan’s latest blockbuster “Interstellar.” Starring Anne Hathaway and Matthew McConaughey, […]

The post Interstellar exploration – five planets where humans may (or may not) be able to live someday appeared first on Smithsonian Insider.

Point your smartphone at the skeleton of a vampire bat mounted in a museum case, wait a minute and you will see it wiggle, jump […]

The post New App adds Virtual Flesh to Victorian-era Bone exhibit appeared first on Smithsonian Insider.

For the first time, astronomers have detected the presence of complex organic molecules, the building blocks of life, in a protoplanetary disk surrounding a young […]

The post Complex Organic Molecules Discovered in Infant Star System appeared first on Smithsonian Insider.

Neanderthals (Homo neanderthalensis) were widespread across Europe and Western Asia for a long time, starting about 400,000 years ago. But things began to change when […]

The post Why did Neanderthals go extinct? appeared first on Smithsonian Insider.

Contrary to popular imagery, massive volcanic eruptions or an asteroid impact may not have been the cause of the world’s first mass extinction. Rather, some […]

The post Did mystery worms cause world’s first mass extinction? appeared first on Smithsonian Insider.

Tucked away on the lower levels of the Smithsonian’s National Museum of Natural History and National Museum of American History are some of science’s most […]

The post Smithsonian Libraries’ rare texts include early superstars of science appeared first on Smithsonian Insider.

Many animals change sex at some point in their lives, often after reaching a certain size. Snails called slipper limpets begin life as males, and […]

The post The Power of Touch: Sex-changing snails switch sooner when together appeared first on Smithsonian Insider.

Scientists at the Smithsonian Institution and partners have published a paper that will help them save Panamanian frog species from extinction due to a deadly […]

The post New Study Helps Smithsonian Scientists Prioritize Frogs at Risk of Extinction appeared first on Smithsonian Insider.

The pink-headed duck was no lucky duck. In 1948 a single specimen of this waterfowl, Rhodonessa caryophyllacea, was donated to the Division of Birds of […]

The post Carotenoid pigments make extinct duck a rare bird indeed appeared first on Smithsonian Insider.

Pop quiz! Name the first five dinosaurs that come to mind. Chances are good that one you named was Tyrannosaurs rex, a popular favorite perhaps best […]

The post New horse-sized tyrannosaur with big brain reveals how “T. rex” became top predator appeared first on Smithsonian Insider.

It is rare but not entirely uncommon to see a manatee swimming in the Atlantic waters of Maryland and Virginia. This one was dead, however, […]

The post In face of mass extinctions, Smithsonian’s Global Genome Initiative quietly saves world’s DNA appeared first on Smithsonian Insider.

Seven fossil teeth exposed by the Panama Canal expansion project are the first evidence of a monkey on the North American continent before the Isthmus […]

The post First North American Monkey Fossils Found in Panama Canal Excavation appeared first on Smithsonian Insider.

The results are in, 2016 is going to be a good year for blue crabs in the Chesapeake Bay. An iconic figure embedded in the […]

The post Smithsonian Expert Urges Caution, Patience on Blue Crab Recovery appeared first on Smithsonian Insider.

One of the primary features that distinguish hominids such as chimpanzees, gorillas and humans from the rest of the animal kingdom are uniquely dexterous hands. […]

The post Did ripening fruit help hominids develop complex hands? appeared first on Smithsonian Insider.

Earlier this year scientists presented evidence for Planet Nine, a Neptune-mass planet in an elliptical orbit 10 times farther from our Sun than Pluto. Since […]

The post Planet 9: A world that should not exist appeared first on Smithsonian Insider.

Thirty years after the scimitar-horned oyrx were driven to extinction, the desert antelope will return to the last-known place it existed: Chad’s Sahelian grasslands. The […]

The post Extinct-in-the-Wild Antelope Return to the Grasslands of Chad appeared first on Smithsonian Insider.

A fossil that has been in the collection of the Smithsonian’s National Museum of Natural History since it was discovered in 1951 is today helping […]

The post New Species of Extinct River Dolphin Discovered in Smithsonian Collection appeared first on Smithsonian Insider.

 The distant planet GJ 1132b intrigued astronomers when it was discovered last year. Located just 39 light-years from Earth, it might have an atmosphere despite […]

The post Venus-like Exoplanet Might Have Oxygen Atmosphere, But Not Life appeared first on Smithsonian Insider.

In 2012, under a scientist’s watchful eye, a comb jelly ate some fish, digested it, and excreted the waste out its back end. In doing […]

The post By simply pooping, comb jellies expel long-held scientific misconception appeared first on Smithsonian Insider.

Food is scarce in the deep, dark regions of the ocean where barbeled dragonfishes and their relatives dwell. Known as the Stomiidae, some of these […]

The post Odd anatomy: flexible joint between skull and spine allow dragonfish to open wide appeared first on Smithsonian Insider.

For centuries, cultures around the world have used masks in ritual dances and festivals to represent traditional characters. This copper mask, found in the Smithsonian’s […]

The post Mexican Masks: Tales Through Dance appeared first on Smithsonian Insider.

Two separate teams of scientists have identified major challenges for the development of life in what has recently become one of the most famous exoplanet […]

The post There’s more to extraterrestrial life than planets in “habitable zone” orbits appeared first on Smithsonian Insider.

Covered in sharp spines, when harassed the porcupine fish inflates like a balloon. Think of a small soccer ball bristling all over with nails. Most predators […]

The post Indestructible jaws from ancient, extinct porcupine fish reveal new species appeared first on Smithsonian Insider.

Hundreds of experiments have shown biodiversity fosters healthier, more productive ecosystems. But many experts doubted whether these experiments would hold up in the real world. […]

The post In the wild, biodiversity’s power surpasses what experiments predict appeared first on Smithsonian Insider.

The next generation of the Sloan Digital Sky Survey (SDSS-V), directed by Juna Kollmeier of the Carnegie Institution for Science, will move forward with mapping […]

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Astronomers had a mystery on their hands. No matter where they looked, from inside the Milky Way to distant galaxies, they observed a puzzling glow […]

The post GBT Detection Unlocks Exploration of ‘Aromatic’ Interstellar Chemistry appeared first on Smithsonian Insider.

 Extinct species don’t usually get a do-over… but don’t tell that to the scimitar-horned oryx. Erased from the wild for three decades, these desert […]

The post Podcast: Don’t call me extinct appeared first on Smithsonian Insider.

In the early 20th century, Canada geese were considered endangered in the U.S. So in the 1950s and 1960s, birds from the Midwest were released […]

The post Study of bacteria inside guts of wild Canada geese shows greater danger than earlier studies exposed appeared first on Smithsonian Insider.

l-Hydroxyproline (l-Hyp) is a nonstandard amino acid that is present in certain proteins, in some antibiotics and in the cell-wall components of plants. l-Hyp is the product of the post-translational modification of protein prolines by prolyl hydroxylase enzymes, and the isomers trans-3-hydroxy-l-proline (T3LHyp) and trans-4-hydroxy-l-proline (T4LHyp) are major components of mammalian collagen. T4LHyp follows two distinct degradation pathways in bacteria and mammals, while T3LHyp is metabolized by a two-step metabolic pathway that is conserved in bacteria and mammals, which involves a T3LHyp dehydratase and a Δ1-pyrroline-2-carboxylate (Pyr2C) reductase. In order to shed light on the structure and catalysis of the enzyme involved in the second step of the T3LHyp degradation pathway, the crystal structure of Pyr2C reductase from the archaeon Thermococcus litoralis DSM 5473 complexed with NADH and l-proline is presented. The model allows the mapping of the residues involved in cofactor and product binding and represents a valid model for rationalizing the catalysis of Pyr2C reductases.

The biological processes related to protein homeostasis in Mycobacterium tuberculosis, the etiologic agent of tuberculosis, have recently been established as critical pathways for therapeutic intervention. Proteins of particular interest are ClpC1 and the ClpC1–ClpP1–ClpP2 proteasome complex. The structure of the potent antituberculosis macrocyclic depsipeptide ecumicin complexed with the N-terminal domain of ClpC1 (ClpC1-NTD) is presented here. Crystals of the ClpC1-NTD–ecumicin complex were monoclinic (unit-cell parameters a = 80.0, b = 130.0, c = 112.0 Å, β = 90.07°; space group P21; 12 complexes per asymmetric unit) and diffracted to 2.5 Å resolution. The structure was solved by molecular replacement using the self-rotation function to resolve space-group ambiguities. The new structure of the ecumicin complex showed a unique 1:2 (target:ligand) stoichiometry exploiting the intramolecular dyad in the α-helical fold of the target N-terminal domain. The structure of the ecumicin complex unveiled extensive interactions in the uniquely extended N-terminus, a critical binding site for the known cyclopeptide complexes. This structure, in comparison with the previously reported rufomycin I complex, revealed unique features that could be relevant for understanding the mechanism of action of these potential antituberculosis drug leads. Comparison of the ecumicin complex and the ClpC1-NTD-L92S/L96P double-mutant structure with the available structures of rufomycin I and cyclomarin A complexes revealed a range of conformational changes available to this small N-terminal helical domain and the minor helical alterations involved in the antibiotic-resistance mechanism. The different modes of binding and structural alterations could be related to distinct modes of action.

Between the world wars of the early Twentieth Century, an age of adventure travel and cultural exploration flourished when newly developed transport and recording technologies–particularly […]

The post New Book: “Recreating First Contact: Expeditions, Anthropology, and Popular Culture” appeared first on Smithsonian Insider.

Photographs, by virtue of their static nature, not only allow us to look back to a fixed point in time, but also give us a […]

The post Book Review: Double Exposure: photos of African American History & Culture appeared first on Smithsonian Insider.

For the first time in its history the Smithsonian’s National Museum of African Art opened an exhibition on the continent of Africa. “Chief S.O. Alonge: […]

The post A first: Smithsonian’s African Art Museum opens exhibition in Africa appeared first on Smithsonian Insider.

Xian Hu, Salma Jalal, Michael Sheetz, Oddmund Bakke, and Felix Margadant

Despite progress made in confocal microscopy, even fast systems still have insufficient temporal resolution for detailed live cell volume imaging, such as tracking rapid movement of membrane vesicles in three-dimensional space. Depending on the shortfall, this may result in undersampling and/or motion artifacts that ultimately limit the quality of the imaging data. By sacrificing detailed information in the Z-direction, we propose a new imaging modality that involves capturing fast "projections" from the field of depth which shortens imaging time by approximately an order of magnitude as compared to standard volumetric confocal imaging. With faster imaging, radiation exposure to the sample is reduced, resulting in less fluorophore photobleaching and potential photodamage. The implementation minimally requires two synchronized control signals that drive a piezo stage and trigger the camera exposure. The device generating the signals has been tested on spinning disk confocals and instant structured-illumination-microscopy (iSIM) microscopes. Our calibration images show that the approach provides highly repeatable and stable imaging conditions that enable photometric measurements of the acquired data, in both standard live imaging and super-resolution modes.

Aline A. Alves, Heloisa B. Gabriel, Maria J. R. Bezerra, Wanderley de Souza, Sue Vaughan, Narcisa L. Cunha-e-Silva, and Jack D. Sunter

Eukaryotic flagella are complex microtubule based organelles and in many organisms there are extra-axonemal structures present, including the outer dense fibres of mammalian sperm and the paraflagellar rod (PFR) of trypanosomes. Flagellum assembly is a complex process occurring across three main compartments, the cytoplasm, the transition fibre-transition zone, and the flagellum. It begins with translation of protein components, followed by their sorting and trafficking into the flagellum, transport to the assembly site and then incorporation. Flagella are formed from over 500 proteins; the principles governing axonemal component assembly are relatively clear. However, the coordination and sites of extra-axonemal structure assembly processes are less clear.

We have discovered two cytoplasmic proteins in T. brucei that are required for PFR formation, PFR assembly factors 1 and 2. Deletion of either PFR-AF1 or PFR-AF2 dramatically disrupted PFR formation and caused a reduction in the amount of major PFR proteins. The presence of cytoplasmic factors required for PFR formation aligns with the concept of processes occurring across multiple compartments to facilitate axoneme assembly and this is likely a common theme for extra-axonemal structure assembly.

Olga Kopach, Noemi Esteras, Selina Wray, Dmitri A. Rusakov, and Andrey Y. Abramov

Frontotemporal dementia and parkinsonism (FTDP-17) caused by the 10+16 splice-site mutation in the MAPT provides an established platform to model tau-related dementia in vitro. Human iPSC-derived neurons have been shown to recapitulate the neurodevelopmental profile of tau pathology during in vitro corticogenesis as in the adult human brain. However, the neurophysiological phenotype of these cells has remained unknown, leaving unanswered questions over the functional relevance and the gnostic power of this disease model. Here we used electrophysiology to explore the membrane properties and intrinsic excitability of the generated neurons to find that human cells mature by ~150 days of neurogenesis to become compatible with matured cortical neurons. In earlier FTDP-17, neurons, however, exhibited a depolarized resting membrane potential associated with increased resistance and reduced voltage-gated Na⁺- and K⁺-channel-mediated conductance. The Na_v1.6 protein was reduced in FTDP-17. These led to a reduced cell capability of induced firing and changed action potential waveform in FTDP-17. The revealed neuropathology may thus contribute to the clinicopathological profile of the disease. This sheds new light on the significance of human models of dementia in vitro.

Laurence Haren, Dorian Farache, Laurent Emorine, and Andreas Merdes

-tubulin is a major protein involved in the nucleation of microtubules in all eukaryotes. It forms two different complexes with proteins of the GCP family (gamma-tubulin complex proteins): -tubulin small complexes (TuSCs), containing -tubulin and GCPs 2 and 3, and -tubulin ring complexes (TuRCs), containing multiple TuSCs, in addition to GCPs 4, 5, and 6. Whereas the structure and assembly properties of TuSCs have been intensively studied, little is known about the assembly of TuRCs, and about the specific roles of GCPs 4, 5, and 6. Here, we demonstrate that two copies of GCP4 and one copy each of GCP5 and GCP6 form a salt-resistant sub-complex within the TuRC that assembles independently of the presence of TuSCs. Incubation of this sub-complex with cytoplasmic extracts containing TuSCs leads to the reconstitution of TuRCs that are competent to nucleate microtubules. In addition, we investigate sequence extensions and insertions that are specifically found at the amino-terminus of GCP6, and between the GCP6 grip1 and grip2 motifs, and we demonstrate that these are involved in the assembly or stabilization of the TuRC.

Sanjeev Chavan Nayak and Vegesna Radha

C3G (RapGEF1) plays a role in cell differentiation and is essential for early embryonic development in mice. In this study, we identify C3G as a centrosomal protein colocalizing with cenexin at the mother centriole in interphase cells. C3G interacts through its catalytic domain with cenexin, and they show interdependence for localization to the centrosome. C3G depletion caused a decrease in cellular cenexin levels. Centrosomal localization is lost as myocytes differentiate to form myotubes. Stable clone of cells depleted of C3G by CRISPR/Cas9 showed the presence of supernumerary centrioles. Overexpression of C3G, or a catalytically active deletion construct inhibited centrosome duplication. Cilia length is longer in C3G knockout cells, and the phenotype could be reverted upon reintroduction of C3G or its catalytic domain. Association of C3G with the basal body is dynamic, decreasing upon serum starvation, and increasing upon reentry into the cell cycle. C3G inhibits cilia formation and length dependent on its catalytic activity. We conclude that C3G inhibits centrosome duplication and maintains ciliary homeostasis, properties that may be important for its role in embryonic development.