A. sediba was discovered in 2008 in the Malapa Cave at the Cradle of Humankind World Heritage Site located outside Johannesburg.

The post Skeletal casts of early hominin ancestor from Africa donated to National Museum of Natural History appeared first on Smithsonian Insider.

In recent research on Santa Rosa Island off the coast of Southern California, isotope readings of carbon and nitrogen found in the bones of Chumash Indians and domestic dogs excavated from archaeological sites show that both humans and dogs have nearly identical signatures of stable isotopes.

The post Ancient bond between humans and dogs revealed in isotopic signatures of their bones appeared first on Smithsonian Insider.

Some--birds called wire-tailed manakins, residents of tropical forests in the Americas--are cooperators as well as competitors. They cooperate, forming alliances for a common cause.

The post Manakins, birds of tropical forests, form alliances for common good appeared first on Smithsonian Insider.

Small tissue samples collected from 238 wild turtles at 15 different locations across their range in Southern Mexico, Belize and Guatemala revealed a “surprising lack” of genetic structure, the scientists write in a recent paper in the journal Conservation Genetics.

The post Endangered river turtle’s genes reveal ancient influence of Maya Indians appeared first on Smithsonian Insider.

This illustration by Carl Buell depicts Ocucajea picklingi (center) and Supayacetus muizoni (bottom), two ancient whales that lived off the Peruvian coast during the Eocene, […]

The post Ancient whales appeared first on Smithsonian Insider.

A fragment of whale rib found in a North Carolina strip mine is offering scientists a rare glimpse at the interactions between prehistoric sharks and whales some 3- to 4- million years ago during the Pliocene.

The post Details of ancient shark attack preserved in fossil whale bone appeared first on Smithsonian Insider.

A new study of marmosets, small South American monkeys, indicates that obesity may begin very early in life and suggests that marmosets may be a helpful model for obesity in humans.

The post Is obesity predestined at infancy? Marmoset study may help scientists find out. appeared first on Smithsonian Insider.

Researchers at the Smithsonian Tropical Research Institute and University of Costa Rica studying why spiders do not stick to their own sticky webs have discovered that a spider's legs are protected by a covering of branching hairs and by a non-stick chemical coating. Their results are published online in the journal, Naturwissenschaften.

The post Fancy footwork and non-stick leg coating helps spiders not stick to their own webs appeared first on Smithsonian Insider.

The scientists made the spiders exercise by irritating them with a small paint brush and causing them to move around until they became exhausted. Spiders from the group with palps removed were able to travel 300 percent further than spiders with their palps intact.

The post Weight of genitals reduces physical endurance in male orb web spiders, researchers find appeared first on Smithsonian Insider.

A new study finds that since 1985, half of Australia's Great Barrier Reef coral has died.

The post Smithsonian marine biologist Nancy Knowlton discusses Great Barrier Reef coral dieoff on PBS NewsHour appeared first on Smithsonian Insider.

What scientists found was that the domestic turkey that ends up on the dinner table exhibits less genetic variation than its ancestral wild counterparts, which were first domesticated in 800 B.C..

The post Today’s domestic turkeys are genetically distinct from wild ancestors appeared first on Smithsonian Insider.

The uplift of the Isthmus of Panama 2.6 million years ago formed a land-bridge that has long thought to be the crucial step in the […]

The post Alligator relatives crossed ancient seaway appeared first on Smithsonian Insider.

Cheeseburgers. Ice cream. French fries. These are a few of the culprits, doctors warn us, responsible for atherosclerosis, a disease commonly known as hardening of […]

The post Ancient mummies reveal atherosclerosis is very likely just a part of aging appeared first on Smithsonian Insider.

Marmosets on track for obesity appeared to be more efficient in their feeding behavior. “Although all animals consumed the same amount of liquid, the ones […]

The post Obese marmosets are more developmentally advanced as infants, study shows appeared first on Smithsonian Insider.

Rooting through the garbage for a late-night snack or stealing food from the cat’s bowl, the suburban raccoon is a nocturnal, intelligent animal. Yet life […]

The post Suburban raccoons more social yet dominance behavior remains that of a solitary animal appeared first on Smithsonian Insider.

For scientists who study non-insect invertebrates, the sheer diversity of these odd and fascinating creatures is both intoxicating and daunting. Occupying niches in habitats the […]

The post Non-insect invertebrates are focus of new global genome-sequencing alliance appeared first on Smithsonian Insider.

Termites and ants are not something you’re likely to pour into a cereal bowl for breakfast or munch with toast and tea, but your ancient […]

The post Termites for breakfast? Your ancestors might have! appeared first on Smithsonian Insider.

National Museum of Natural History scientist Torsten Dikow discovered and named a new species of assassin fly, Burmapogon bruckschi, after studying the first two specimens […]

The post Ancient species of assassin fly discovered by Smithsonian scientist appeared first on Smithsonian Insider.

A newly-discovered species of ant supports a controversial theory of species formation. The ant, known to live only under a single eucalyptus tree on the […]

The post Deadbeat ant species branched off as parasite inside its own colony appeared first on Smithsonian Insider.

A few images of comet 67P/Churyumov-Gerasimenko just sent back by the European spaceship Rosetta appear to be a snowboarder’s dream: pristine slopes covered in powder. […]

The post Comet probe set to answer ancient question of life on earth appeared first on Smithsonian Insider.

Yabbies, mudbugs, crayfish, crawdads, call them what you will, but one-third of the world’s crayfish species are facing extinction according to a recent report by […]

The post Coming soon: Vacancy at the crawdad hole? appeared first on Smithsonian Insider.

Tiny Anolis lizards preserved since the Miocene in amber are giving scientists a true appreciation of the meaning of community stability. Dating back some 15 […]

The post Trapped in Amber: Ancient fossils reveal remarkable stability of Caribbean lizard communities appeared first on Smithsonian Insider.

Smithsonian scientists and colleagues have discovered a new genus and species of river dolphin that has long been extinct. They made the discovery after carefully […]

The post Fossil Specimen Reveals a New Species of Ancient River Dolphin appeared first on Smithsonian Insider.

If you were dumped into the middle of a desert, your first instinct would be to look for water—it is, after all, the stuff of […]

The post In Western China’s deserts an ancient competition for water resumes appeared first on Smithsonian Insider.

The Mojave Desert and Death Valley are among the hottest, driest places in North America. So how might climate change impact a resilient reptile that […]

The post Warming may shrink ancient range of heat loving desert lizard appeared first on Smithsonian Insider.

New research by a team of archaeologists has revealed a curious connection between our traditional Thanksgiving dinner and the taste buds of prehistoric mammoths and […]

The post Study reveals ancient link between mammoth dung and pumpkin pie appeared first on Smithsonian Insider.

The debate about the world’s oldest tattoos is over—they belong to Ötzi, the European Tyrolean Iceman who died and was buried beneath an Alpine glacier […]

The post Ancient Ink: Iceman Otzi Has World’s Oldest Tattoos appeared first on Smithsonian Insider.

Bald from snout to tail with baggy wrinkled skin and beady eyes, eastern African naked mole rats (Heterocephalus glaber) are subterranean mammals long credited with […]

The post Rare cancer cells discovered in naked mole rats appeared first on Smithsonian Insider.

Nocturnal, solitary and fiercely territorial the adult Egyptian pigmy shrew—one of the smallest mammals on earth—weighs just 7 grams. French zoologist Isidore Geoffroy Saint-Hilaire first […]

The post Sacred shrew mummies reveal species distribution in ancient Egypt 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.

Finding clean ways to store water is a challenge that humans have faced for millennia. In a new paper in Environmental Health, anthropologist Sabrina Sholts […]

The post Study shows ancient California Indians risked toxins from bitumen-coated bottles 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.

Cats are notoriously fickle—purring in your lap one second, then swiping you with an indignant claw the next. One thing is certain however when it […]

The post Eons before viral kitten videos, ancient Egyptians adored cats appeared first on Smithsonian Insider.

A bat specimen collected in France at the end of World War I, since housed in the collections of the Smithsonian’s National Museum of Natural […]

The post DNA on 100-year-old bat from France may help fight deadly fungus in North America appeared first on Smithsonian Insider.

A new study from the Smithsonian Conservation Biology Institute (SCBI) is helping make headway in an area of animal management that has historically proven challenging: […]

The post Early indicator of cheetah pregnancy identified appeared first on Smithsonian Insider.

As command module pilot for the Apollo 15 mission to the moon in 1971, Al Worden spent six days orbiting the moon, including three days completely alone, the most isolated human in existence. In Falling to Earth, Worden tells for the first time the full story around the dramatic events that shook NASA and ended his spaceflight career.

The post “Falling to Earth: An Apollo 15 Astronaut’s Journey to the Moon” by Al Worden with Francis French appeared first on Smithsonian Insider.

Yinlong Song, Yikan Zhang, Ying Pan, Jianfeng He, Yan Wang, Wei Chen, Jing Guo, Haiteng Deng, Yi Xue, Xianyang Fang, and Xin Liang

Microtubules dynamics is regulated by the plus end-tracking proteins (+TIPs) in cells. End binding protein 1 (EB1) acts as a master regulator in +TIPs networks by targeting microtubule growing ends and recruiting other factors. However, the molecular mechanism of how EB1 binds to microtubule ends with a high affinity remains to be an open question. Using single-molecule imaging, we show that the end-binding kinetics of EB1 changes along with the polymerizing and hydrolysis rate of tubulin dimers, confirming the binding of EB1 to GTP/GDP-Pi tubulin at microtubule growing ends. The affinity of wild-type EB1 to these sites is higher than monomeric EB1 mutants, suggesting that two CH domains in the dimer contribute to the end-binding. Introducing phosphomimicking mutations into the linker domain of EB1 weakens the end-binding affinity and confers a more curved conformation to EB1 dimer without compromising dimerization, suggesting that the overall architecture of EB1 is important for the end-binding affinity. Taken together, our results provide insights into understanding how the high-affinity end-binding of EB1 can be achieved and how this activity may be regulated in cells.

David Guerit, Pauline Marie, Anne Morel, Justine Maurin, Christel Verollet, Brigitte Raynaud-Messina, Serge Urbach, and Anne Blangy

Among hematopoietic cells, osteoclasts (Oc) and immature dendritic cells (Dc) are closely related myeloid cells with distinct functions; Oc participate skeleton maintenance while Dc sample the environment for foreign antigens. Such specificities rely on profound modifications of gene and protein expression during Oc and Dc differentiation. We provide global proteomic and transcriptomic analyses of primary mouse Oc and Dc, based on original SILAC and RNAseq data. We established specific signatures for Oc and Dc including genes and proteins of unknown functions. In particular, we showed that Oc and Dc have the same α and β tubulin isotypes repertoire but that Oc express much more β tubulin isotype Tubb6. In both mouse and human Oc, we demonstrate that elevated expression of Tubb6 in Oc is necessary for correct podosomes organization and thus for the structure of the sealing zone, which sustains the bone resorption apparatus. Hence, lowering Tubb6 expression hindered Oc resorption activity. Overall, we highlight here potential new regulators of Oc and Dc biology and illustrate the functional importance of the tubulin isotype repertoire in the biology of differentiated cells.

Bipasha Dey and Richa Rikhy

Cell shape morphogenesis from spherical to polygonal occurs in epithelial cell formation in metazoan embryogenesis. In syncytial Drosophila embryos, the plasma membrane incompletely surrounds each nucleus and is organized as a polygonal epithelial-like array. Each cortical syncytial division cycle shows circular to polygonal plasma membrane transition along with furrow extension between adjacent nuclei from interphase to metaphase. In this study, we assess the relative contribution of DE-cadherin and Myosin II at the furrow for polygonal shape transition. We show that polygonality initiates during each cortical syncytial division cycle when the furrow extends from 4.75 to 5.75 µm. Polygon plasma membrane organization correlates with increased junctional tension, increased DE-cadherin and decreased Myosin II mobility. DE-cadherin regulates furrow length and polygonality. Decreased Myosin II activity allows for polygonality to occur at a lower length than controls. Increased Myosin II activity leads to loss of lateral furrow formation and complete disruption of polygonal shape transition. Our studies show that DE-cadherin-Myosin II balance regulates an optimal lateral membrane length during each syncytial cycle for polygonal shape transition.

Karolina Losenkova, Mariachiara Zuccarini, Marika Karikoski, Juha Laurila, Detlev Boison, Sirpa Jalkanen, and Gennady G. Yegutkin

Extracellular adenosine mediates diverse anti-inflammatory, angiogenic and vasoactive effects and becomes an important therapeutic target for cancer, which has been translated into clinical trials. This study was designed to comprehensively assess adenosine metabolism in prostate and breast cancer cells. We identified cellular adenosine turnover as a complex cascade, comprised of (a) the ectoenzymatic breakdown of ATP via sequential nucleotide pyrophosphatase/phosphodiesterase-1, ecto-5’-nucleotidase/CD73 and adenosine deaminase reactions, and ATP re-synthesis through counteracting adenylate kinase and nucleoside diphosphokinase; (b) the uptake of nucleotide-derived adenosine via equilibrative nucleoside transporters; and (c) the intracellular adenosine phosphorylation into ATP by adenosine kinase and other nucleotide kinases. The exposure of cancer cells to 1% O₂ for 24 hours triggered ~2-fold up-regulation of CD73, without affecting nucleoside transporters, adenosine kinase activity and cellular ATP content. The ability of adenosine to inhibit the tumor-initiating potential of breast cancer cells via receptor-independent mechanism was confirmed in vivo using a xenograft mouse model. The existence of redundant pathways controlling extracellular and intracellular adenosine provides a sufficient justification for reexamination of the current concepts of cellular purine homeostasis and signaling in cancer.

Ganlu Deng, Yihong Chen, Cao Guo, Ling Yin, Ying Han, Yiyi Li, Yaojie Fu, Changjing Cai, Hong Shen, and Shan Zeng

Epithelial-mesenchymal transition (EMT) is a crucial process for cancer cells to acquire metastatic potential, which primarily causes death in gastric cancer (GC) patients. Bone morphogenetic protein 4 (BMP4) is a member of the TGF-β family that plays an indispensable role in human cancers. However, little is known about its roles in GC metastasis. In this study, BMP4 was found to be frequently overexpressed in GC tissues and was correlated with patient's poor prognosis. BMP4 was upregulated in GC cell lines and promoted EMT and metastasis of GC cells both in vitro and in vivo, while knockdown of BMP4 significantly inhibited EMT and metastasis of GC cells. Meanwhile, the inhibitor of DNA binding 1 (Id1) was identified as a downstream target of BMP4 by PCR arrays and upregulated via Smad1/5/8 phosphorylation. Id1 knockdown attenuated BMP4-induced EMT and invasion in GC cells. Moreover, Id1 overexpression in BMP4 knockdown cells restored the promotion of EMT and cell invasion. In summary, BMP4 induced EMT to promote GC metastasis by upregulating Id1 expression. Antagonizing BMP4 may be a potential therapeutic strategy in GC metastasis.

Formed some 250,000 years ago when the Nile River pushed through a low channel near Wadi Tushka, it flooded the eastern Sahara, creating a lake that at its highest level covered more than 42,000 square miles.

The post Ancient megalake discovered beneath Sahara Desert appeared first on Smithsonian Insider.

Many traits unique to humans were long thought to have originated in the genus Homo between 2.4 and 1.8 million years ago in Africa. A […]

The post Human Evolution Rewritten: We owe our existence to our ancestor’s flexible response to climate change appeared first on Smithsonian Insider.

Oysters are keystone organisms in estuaries around the world, influencing water quality, constructing habitat and providing food for humans and wildlife. Yet their populations in […]

The post Ancient Native-American methods may be key to sustainable oyster harvests appeared first on Smithsonian Insider.

The last time Earth experienced both ice sheets and carbon dioxide levels within the range predicted for this century was a period of major sea […]

The post What the Ancient CO2 Record May Mean for Future Climate Change appeared first on Smithsonian Insider.

To the Hopewell Culture, ancient Native Americans who sought out the exotic from near and far, metal was a rare and precious resource. Copper, found […]

The post Ancient Native American beads traced to otherworldy source: an iron meteorite appeared first on Smithsonian Insider.

Tom Crouch, Senior curator in the National Air and Space Museum's Aeronautics Division, discusses Thaddeus Lowe and the birth of American aerial reconnaissance during the Civil War. This presentation was recorded on May 11, 2011 on the National Mall.

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The post 3-D laser scanning is helping solve ancient mysteries at the Smithsonian appeared first on Smithsonian Insider.