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Updated: 53 min 16 sec ago
Our DNA and its architecture are duplicated every time our cells divide. Histone proteins are key building blocks of this architecture and contain crucial information that regulates our genes. Danish researchers show how an enzyme controls reliable and high-speed delivery of histones to DNA copying hubs in our cells. This shuttling mechanism is crucial to maintain normal function of our genes and prevent disease. The results are published in the journal Nature Communications.
This shows the North Atlantic tracking routes of 17 juvenile loggerhead sea turtles. A new study satellite tracked 17 young loggerhead turtles in the Atlantic Ocean to better understand sea turtle nursery grounds and early habitat use during the 'lost years.' The study, conducted by a collaborative research team, including scientists from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, was the first long-term satellite tracking study of young turtles at sea.
Papilio polytes, an Asian swallowtail butterfly species also known as the Common Mormon, possesses distinctive mimicry patterns (left). The same species also has non-mimetic forms (right). A single gene regulates the complex wing patterns, colors and structures required for mimicry in swallowtail butterflies, report scientists from the University of Chicago, March 5 in Nature. Surprisingly, the gene described, doublesex, is already well-known for its critical role in sexual differentiation in insects.
Lentiviruses, which belong to the family of retroviruses, are used as vectors to exchange genetic material in cells and can be used to replace a defective gene as defined by gene therapy. Increasing the efficiency of such a treatment poses a major medical challenge: the virus should specifically track the target cells, but the number of virus used should be as low as possible.
In the heart muscle cell above, the arrows show an early sign of replication. In a study that began in a pair of infant siblings with a rare heart defect, Johns Hopkins researchers say they have identified a key molecular switch that regulates heart cell division and normally turns the process off around the time of birth. Their research, they report, could advance efforts to turn the process back on and regenerate heart tissue damaged by heart attacks or disease.
Researchers at Columbia University have made a significant step toward visualizing small biomolecules inside living biological systems with minimum disturbance, a longstanding goal in the scientific community. In a study published March 2nd in Nature Methods, Assistant Professor of Chemistry Wei Min's research team has developed a general method to image a broad spectrum of small biomolecules, such as small molecular drugs and nucleic acids, amino acids, lipids for determining where they are localized and how they function inside cells.
Göttingen-based scientists working at DESY's PETRA III research light source have carried out the first studies of living biological cells using high-energy X-rays. The new method shows clear differences in the internal cellular structure between living and dead, chemically fixed cells that are often analysed. "The new method for the first time enables us to investigate the internal structures of living cells in their natural environment using hard X-rays," emphasises the leader of the working group, Prof. Sarah Köster from the Institute for X-Ray Physics of the University of Göttingen. The researchers present their work in the scientific journal Physical Review Letters.
A new report appearing in the March 2014 issue of The FASEB Journal helps shed light on what drives the evolution of pathogens, as well as how our bodies adapt to ward them off. Specifically, the report shows that our bodies naturally employ a mechanism, called "CD33rSiglecs," that not only dampens unwanted immune responses against one's own cells, but also evolves rapidly to recognize foreign invaders. What's more, the report explains how pathogens exploit this immunological "vulnerability" of "self-recognition" to evade our bodies' defenses. This leads to a seemingly endless "arms race" between constantly evolving pathogens and immune systems. Understanding this phenomenon may become crucial for developing novel drugs against various pathogens that try to take advantage of this system.
Stars, diamonds, circles. Rather than your average bowl of Lucky Charms, these are three-dimensional cell cultures generated by an exciting new digital microfluidics platform, the results of which have been published in Nature Communications this week by researchers at the University of Toronto. The tool, which can be used to study cells in cost-efficient, three-dimensional microgels, may hold the key to personalized medicine applications in the future.
With antibiotic resistant infections on the rise and a scarce pipeline of novel drugs to combat them, researchers at the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center (LA BioMed) are pursuing entirely new approaches to meet the challenge of drug-resistant infections by taming microbes rather than killing them.
Researchers from Princeton University and Washington University in St. Louis report that the unusual arrangement of cells in a chicken's eye constitutes the first known biological occurrence of a potentially new state of matter known as "disordered hyperuniformity," which has been shown to have unique physical properties. These states have a "hidden order" that allows them to behave like crystal and liquid states of matter. They exhibit order over large distances and disorder over small distances. This diagram depicts the spatial distribution of the five types of light-sensitive cells known as cones in the chicken retina. Along with eggs, soup and rubber toys, the list of the chicken's most lasting legacies may eventually include advanced materials such as self-organizing colloids, or optics that can transmit light with the efficiency of a crystal and the flexibility of a liquid.
Engineers like to make things that work. And if one wants to make something work using nanoscale components—the size of proteins, antibodies, and viruses—mimicking the behavior of cells is a good place to start since cells carry an enormous amount of information in a very tiny packet. As Erik Winfree, professor of computer science, computation and neutral systems, and bioengineering, explains, "I tend to think of cells as really small robots. Biology has programmed natural cells, but now engineers are starting to think about how we can program artificial cells. We want to program something about a micron in size, finer than the dimension of a human hair, that can interact with its chemical environment and carry out the spectrum of tasks that biological things do, but according to our instructions."
The power of regenerative medicine now allows scientists to transform skin cells into cells that closely resemble heart cells, pancreas cells and even neurons. However, a method to generate cells that are fully mature—a crucial prerequisite for life-saving therapies—has proven far more difficult. But now, scientists at the Gladstone Institutes and the University of California, San Francisco (UCSF), have made an important breakthrough: they have discovered a way to transform skin cells into mature, fully functioning liver cells that flourish on their own, even after being transplanted into laboratory animals modified to mimic liver failure.
In blue are Plasmodium falciparum malaria parasites in the sexual, gametocyte stage of development. In red are uninfected red blood cells. Two teams have independently discovered that a single regulatory protein acts as the master genetic switch that triggers the development of male and female sexual forms (termed gametocytes) of the malaria parasite, solving a long-standing mystery in parasite biology with important implications for human health. The protein, AP2-G, is necessary for activating a set of genes that initiate the development of gametocytes -- the only forms that are infectious to mosquitos. The research also gives important clues for identifying the underlying mechanisms that control this developmental fate, determining whether or not a malaria parasite will be able to transmit the disease.
Caltech researchers separate blood stem cells from other bone marrow cells and load them onto a newly developed microfluidic chip. Fluorescent signals indicate the presence of secreted proteins with one... In the battle against infection, immune cells are the body's offense and defense—some cells go on the attack while others block invading pathogens. It has long been known that a population of blood stem cells that resides in the bone marrow generates all of these immune cells. But most scientists have believed that blood stem cells participate in battles against infection in a delayed way, replenishing immune cells on the front line only after they become depleted.
This is a photo of Brookhaven National Laboratory biochemist Chang-Jun Liu with Mingyue Gou, Huijun Yang, Yuanheng Cai and Xuebin Zhang. Plant growth is orchestrated by a spectrum of signals from hormones within a plant. A major group of plant hormones called cytokinins originate in the roots of plants, and their journey to growth areas on the stem and in leaves stimulates plant development. Though these phytohormones have been identified in the past, the molecular mechanism responsible for their transportation within plants was previously poorly understood.