The panel starts speaking at about minute 14. The technical presentation of the video could be better (likely will be as we develop good, easy ways to capture speaking events for web delivery) but their is some interesting content.
Related: Microbes – Secret Life of Microbes – SciVee: Science Webcasts – Plants, Unikonts, Excavates and SARs
Discovery of Giant Roaming Deep Sea Protist Provides New Perspective on Animal Evolution
Biologist Mikhail “Misha” Matz and his colleagues recently discovered the grape-sized protists and their complex tracks on the ocean floor near the Bahamas. DNA analysis confirmed that the giant protist found by Matz and his colleagues in the Bahamas is Gromia sphaerica, a species previously known only from the Arabian Sea.
Matz says the protists probably move by sending leg-like extensions, called pseudopodia, out of their cells in all directions. The pseudopodia then grab onto mud in one direction and the organism rolls that way, leaving a track. Hr says the giant protists’ bubble-like body design is probably one of the planet’s oldest macroscopic body designs, which may have existed for 1.8 billion years.
“I personally think now that the whole Precambrian may have been exclusively the reign of protists,” says Matz. “Our observations open up this possible way of interpreting the Precambrian fossil record.”
He says the appearance of all the animal body plans during the Cambrian explosion might not just be an artifact of the fossil record. There are likely other mechanisms that explain the burst-like origin of diverse multicellular life forms.
Single-Celled Giant Upends Early Evolution
A distant relative of microscopic amoebas, the grape-sized Gromia sphaerica was discovered once before, lying motionless at the bottom of the Arabian Sea. But when Mikhail Matz of the University of Texas at Austin and a group of researchers stumbled across a group of G. sphaerica off the coast of the Bahamas, the creatures were leaving trails behind them up to 50 centimeters (20 inches) long in the mud.
The trouble is, single-celled critters aren’t supposed to be able to leave trails. The oldest fossils of animal trails, called ‘trace fossils’, date to around 580 million years ago, and paleontologists always figured they must have been made by multicellular animals with complex, symmetrical bodies.
Related: Lancelet Genome Provides Answers on Evolution – MicroRNAs Emerged Early in Evolution – Fossils of Sea Monster – Sea Urchin Genome
Developed more than 200 years ago and found in households around the world, chlorine bleach is among the most widely used disinfectants, yet scientists never have understood exactly how the familiar product kills bacteria. In fact, Hypochlorite, the active ingredient of household bleach, attacks essential bacterial proteins, ultimately killing the bugs.
“As so often happens in science, we did not set out to address this question,” said Jakob, an associate professor of molecular, cellular and developmental biology. “But when we stumbled on the answer midway through a different project, we were all very excited.”
Jakob and her team were studying a bacterial protein known as heat shock protein 33 (Hsp33), which is classified as a molecular chaperone. The main job of chaperones is to protect proteins from unfavorable interactions, a function that’s particularly important when cells are under conditions of stress, such as the high temperatures that result from fever.
“At high temperatures, proteins begin to lose their three-dimensional molecular structure and start to clump together and form large, insoluble aggregates, just like when you boil an egg,” said lead author Jeannette Winter, who was a postdoctoral fellow in Jakob’s lab. And like eggs, which once boiled never turn liquid again, aggregated proteins usually remain insoluble, and the stressed cells eventually die.
Jakob and her research team figured out that bleach and high temperatures have very similar effects on proteins. Just like heat, the hypochlorite in bleach causes proteins to lose their structure and form large aggregates.
These findings are not only important for understanding how bleach keeps our kitchen countertops sanitary, but they may lead to insights into how we fight off bacterial infections. Our own immune cells produce significant amounts of hypochlorite as a first line of defense to kill invading microorganisms. Unfortunately, hypochlorite damages not just bacterial cells, but ours as well. It is the uncontrolled production of hypochlorite acid that is thought to cause tissue damage at sites of chronic inflammation.
How did studying the protein Hsp33 lead to the bleach discovery? The researchers learned that hypochlorite, rather than damaging Hsp33 as it does most proteins, actually revs up the molecular chaperone. When bacteria encounter the disinfectant, Hsp33 jumps into action to protect bacterial proteins against bleach-induced aggregation.
“With Hsp33, bacteria have evolved a very clever system that directly senses the insult, responds to it and increases the bacteria’s resistance to bleach,” Jakob said.
Related: University of Michigan Press release – How do antibiotics kill bacteria? – NPR podcast on the story – Why ‘Licking Your Wounds’ Works – Researchers Learn What Sparks Plant Growth
Marine microorganisms have been found in amber dating from the middle of the Cretaceous period. The fossils were collected in Charente, in France. This completely unexpected discovery will deepen our understanding of these lost marine species as well as providing precious data about the coastal environment of Western France during the Cretaceous. This work was carried out by researchers at the Géosciences Rennes laboratory, together with researchers from the Paléobiodiversité et Paléoenvironnement laboratory in Paris and the Centre de Géochimie de la Surface in Strasbourg.
Amber is a fossil resin with a reputation for preserving even the most minute details of insects and other terrestrial arthropods (spiders, scorpions, mites) that lived in resiniferous trees. The forest-based provenance of amber in theory makes it impossible for marine animals to be trapped in the resin. Nonetheless, researchers from the Géosciences Rennes laboratory have discovered various inclusions of marine plankton in amber from the Mid-Cretaceous (100 to 98 million years ago). These micro-organisms are found in just a few pieces of amber among the thousands that have been studied, but show a remarkable diversity: unicellular algae, mainly diatoms found in large numbers, traces of animal plankton, such as radiolaria and a foraminifer, spiny skeletons of sponges and of echinoderms.
Foraminifera (the photo shows one in Amber) are amoeboid protists with reticulating pseudopods, fine strands of cytoplasm that branch and merge to form a dynamic net.[1] They typically produce a test, or shell, which can have either one or multiple chambers, some becoming quite elaborate in structure.[2] These shells are made of calcium carbonate (CaCO3) or agglutinated sediment particles. About 275,000 species are recognized, both living and fossil.[citation needed] They are usually less than 1 mm in size.”
Carried out together with researchers at the Muséum national d’histoire naturelle, the study of diatoms pushed back by 10 to 30 million years the known date for the appearance of certain marine forms of this type of algae. This new information, taken together with recent data on molecular phylogeny, marks a huge advance in our understanding of the complex evolutionary history of diatoms.
The presence of these marine organisms in the amber is an ecological paradox. How did these marine species become stuck and then trapped in the conifers’ resin? The most likely scenario is that the forest producing the amber was very close to the coast, potentially shrouded by plankton-bearing mist or flooded by sea water during storms.
The preservation of marine organisms in amber is an exceptional asset, allowing us to deepen our understanding of these lost species and to have a clear idea about the coastal environment of Western France during the Cretaceous.
Related: Dino-Era Feathers Found Encased in Amber – 2,000 year old living coral – Bdelloid Rotifers Abandoned Sex 100 Million Years Ago
Gut Bacteria May Cause And Fight Disease, Obesity
But as soon as we pass out of the birth canal, when we are fetched by a doctor’s hands, placed in a hospital crib, put on our mother’s breast, when we drag a thumb across a blanket and stick that thumb in our mouths, when we swallow our first soft food, we are invaded by all sorts of bacteria. Once inside, they multiply – until the bacteria inside us outnumber our human cells.
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University of Chicago immunologist Alexander Chervonsky, with collaborators from Yale University, recently reported that doses of the right stomach bacteria can stop the development of type 1 diabetes in lab mice. “By changing who is living in our guts, we can prevent type 1 diabetes,” he told The Wall Street Journal.
The bottom line: We now have two sets of genes to think about – the ones we got from our parents and the ones of organisms living inside us. Our parents’ genes we can’t change, but the other set? Now that is one of the newest and most exciting fields in cell biology.
Follow link with related podcast: Gut bacteria may cause and fight, disease, obesity. This whole area of the ecosystem within us and our health I find fascinating. And I fall for confirmation bias on things like becoming inefficient at converting food to energy as a way reduce obesity.
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They then gave an example of the difference being 95 calories versus 99 calories. Hardly seems huge but it would add up. Still that is a less amazing difference than I was expecting.
Related: Energy Efficiency of Digestion – Waste from Gut Bacteria Helps Host Control Weight – Obesity Epidemic Partially Explained – Foreign Cells Outnumber Human Cells in Our Bodies
“Once we saw him juggling the hermit crabs in his tank, another time he threw stones against the glass damaging it. And from time to time he completely re-arranges his tank to make it suit his own taste better – much to the distress of his fellow tank inhabitants.”
Related: more fun posts – The Brine Lake Beneath the Sea – Baby Sand Dollars Clone Themselves When They Sense Danger – Virgin Birth for Another Shark Species
Copper door handles and taps kill 95% of superbugs in hospitals
Related: Anti-microbial ‘paint’ – Antimicrobial Wipes Often Spread Bacteria – Attacking Bacterial Walls
In January, she will compare the Russian population’s DNA to that of other populations and other species to confirm her suspicions. “Based on geography, based on behavior, and based on a phenotypic variation we saw in the wing pattern, we can speculate that this represents something different, something new,” Zaspel said.
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Only male moths exhibit blood feeding, she noted, raising the possibility that as in some species of butterflies and other moths, the Russian moths do it to pass on salt to females during copulation.
“There is no evidence it prolongs the life of the male, or anything like that,” she said. “So we suspect that it is probably going to the female.” The sexual gift, she said, would provide a nutritional boost to young larvae that feed on leaf-rich, but sodium-poor, diets.
Related: Darwin’s Orchid Prediction – Why Insects Can’t Fly Straight at Night – Eat Less Salt to Save Your Heart
Scientists Come Closer to Unlocking Secrets of Common Cold
Instead, the ubiquitous virus alters the activity of genes in the body, which then results in the misery that afflicts most people every year or so, according to a study in the first November issue of the American Journal of Respiratory and Critical Care Medicine.
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Human rhinovirus (HRV) causes some 30 percent to 50 percent of common colds and can also worsen more serious conditions, such as asthma.
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A “microarray analysis” of DNA showed no genetic changes eight hours after infection. But, after two days, about 6,500 genes had been affected, either with heightened activity or dampened activity.
The genes most affected by the presence of the virus were ones that make antiviral proteins and pro-inflammatory chemicals that contribute to airway inflammation, the researchers said.
Read: Learning How Viruses Evade the Immune System – Gene Carnival – Black Raspberries Alter Hundreds of Genes Slowing Cancer – Study Finds No Measurable Benefit to Flu Shots
Related: Scientists Search for Clues To Bee Mystery – Virus Found to be One Likely Factor in Bee Colony Collapse Disorder – Royal Ant Genes