Molecular & Cell Biology

Category: Molecular & Cell Biology

UCSF scientists controlled seizures in epileptic mice with a one-time transplantation of medial ganglionic eminence (MGE) cells, which inhibit signaling in overactive nerve circuits, into the hippocampus, a brain region associated with seizures, as well as with learning and memory. Other researchers had previously used different cell types in rodent cell transplantation experiments and failed to stop seizures.

When a mouse smells a cat, it instinctively avoids the feline or risks becoming dinner. How? A Northwestern University study involving olfactory receptors, which underlie the sense of smell, provides evidence that a single gene is necessary for the behavior.

Researcher Johan Jakobsson and his colleagues have now published their results in Nature Communications.

For a long time, scientists have dreamt of converting undesirable white fat cells into brown fat cells and thus simply have excess pounds melt away. Researchers at the University of Bonn have now gotten a step closer to this goal: They decoded a "toggle switch" in mice which can significantly stimulate fat burning. The results are now being presented in the scientifc journal "Nature Communications".


These is a false color image of the skin showing newly discovered immune cells, which have a potential link to allergic skin diseases like eczema.
Sydney researchers have discovered a new type of immune cell in skin that plays a role in fighting off parasitic invaders such as ticks, mites, and worms, and could be linked to eczema and allergic skin diseases.

Researchers at the Stanford University School of Medicine have succeeded in transforming skin cells directly into oligodendrocyte precursor cells, the cells that wrap nerve cells in the insulating myelin sheaths that help nerve signals propagate.

Researchers at Lund University in Sweden have discovered a new protein that controls the presence of the Vel blood group antigen on our red blood cells. The discovery makes it possible to use simple DNA testing to find blood donors for patients who lack the Vel antigen and need a blood transfusion.

Isolation of DNA from some organisms is a routine procedure. For example, you can buy a kit at your local pharmacy or grocery store that allows you to swab the inside of your cheek and send the sample for DNA sequencing. However, for other organisms, DNA extraction is much more problematic. Researchers at Desert Botanical Garden in Phoenix, Arizona, have developed a novel procedure that greatly simplifies genomic DNA isolation from cactus tissue.


Eva Nogales and Yuan He used cryo-electron microscopy to record how a complex of biomolecules is able to read the human genome one gene at a time.
Researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) have achieved a major advance in understanding how genetic information is transcribed from DNA to RNA by providing the first step-by-step look at the biomolecular machinery that reads the human genome.

Long segments of RNA— encoded in our DNA but not translated into protein—are key to physically manipulating DNA in order to activate certain genes, say researchers at The Wistar Institute. These non-coding RNA-activators (ncRNA-a) have a crucial role in turning genes on and off during early embryonic development, researchers say, and have also been connected with diseases, including some cancers, in adults.


This is a DNA structure as seen through the 4-D electron microscope invented at Caltech.
Every great structure, from the Empire State Building to the Golden Gate Bridge, depends on specific mechanical properties to remain strong and reliable. Rigidity—a material's stiffness—is of particular importance for maintaining the robust functionality of everything from colossal edifices to the tiniest of nanoscale structures. In biological nanostructures, like DNA networks, it has been difficult to measure this stiffness, which is essential to their properties and functions. But scientists at the California Institute of Technology (Caltech) have recently developed techniques for visualizing the behavior of biological nanostructures in both space and time, allowing them to directly measure stiffness and map its variation throughout the network.


Mitochondria (bright areas) are visible in these stained fruit fly ovary cells.
Diseases from a mutation in one genome are complicated enough, but some illnesses arise from errant interactions between two genomes: the DNA in the nucleus and in the mitochondria. Scientists want to know more about how such genomic disconnects cause disease. In a step in that direction, scientists at Brown University and Indiana University have traced one such incompatibility in fruit flies down to the level of individual nucleotide mutations and describe how the genetic double whammy makes the flies sick.

Just like a comic book super hero, you could say that the enzyme superoxide dismutase (SOD1) has a secret identity. Since its discovery in 1969, scientists believed SOD1's only role was to protect living cells against damage from free radicals. Now, researchers at the Johns Hopkins Bloomberg School of Public Health have discovered that SOD1 protects cells by regulating cell energy and metabolism. The results of their research were published January 17, 2013, in the journal Cell.

When researchers sequence the RNA of cancer cells, they can compare it to normal cells and see where there is more RNA. That can help lead them to the gene or protein that might be triggering the cancer.


Dendritic cells, shown here in an electron microscopic picture, need antibodies produced by B cells for their maturation.
Dendritic cells, or DCs for short, perform a vital role for the immune system: They engulf pathogens, break them down into their component parts, and then display the pieces on their surface. This in turn signals other immune cells capable of recognizing these pieces to help kick-start their own default program for fighting off the invaders. In order to do their job, the DCs are dependent upon the support from a class of immune system molecules, which have never before been associated with dendritic cells: antibodies, best known for their role in vaccinations and diagnostics. Now, scientists at the Helmholtz Centre for Infection Research (HZI) and the Hannover Medical School (MHH) were able to show that antibodies are essential for dendritic cell maturation. The researchers' findings have been published in the renowned scientific journal, Proceedings of the National Academy of Sciences (PNAS).


This is an illustration of what happens when viral DNA enters the nucleus of a cell with low dUTP levels (left) versus high dUTP levels (right).
A team of researchers based at Johns Hopkins has decoded a system that makes certain types of immune cells impervious to HIV infection. The system's two vital components are high levels of a molecule that becomes embedded in viral DNA like a code written in invisible ink, and an enzyme that, when it reads the code, switches from repairing the DNA to chopping it up into unusable pieces. The researchers, who report the find in the Jan. 21 early edition of the Proceedings of the National Academy of Sciences, say the discovery points toward a new approach to eradicating HIV from the body.


This shows the expression of the chromokinesin NOD (red) stabilizes aberrant interactions between kinetochores and spindle microtubules (green). Tension stabilizes bioriented attachments where each sister chromatid is attached to microtubules.
Studies led by cell biologist Thomas Maresca at the University of Massachusetts Amherst are revealing new details about a molecular surveillance system that helps detect and correct errors in cell division that can lead to cell death or human diseases. Findings are reported in the current issue of the Journal of Cell Biology.

Biomedical researchers studying aging and cancer are intensely interested in telomeres, the protective caps on the ends of chromosomes. In a new study, scientists at UC Santa Cruz used a novel technique to reveal structural and mechanical properties of telomeres that could help guide the development of new anti-cancer drugs.

Every time a human or bacterial cell divides it first must copy its DNA. Specialized proteins unzip the intertwined DNA strands while others follow and build new strands, using the originals as templates. Whenever these proteins encounter a break – and there are many – they stop and retreat, allowing a new cast of molecular players to enter the scene.


Thousand of epigenetic switches in the liver control whether genes turn on or off in response to circadian cycles. The figure illustrates daily changes, every six hours, in five different...
When it's dark, and we start to fall asleep, most of us think we're tired because our bodies need rest. Yet circadian rhythms affect our bodies not just on a global scale, but at the level of individual organs, and even genes.

DNA, like houses and cars, needs ongoing maintenance. Rays of ultraviolet sunlight, chemical pollutants and normal biochemical processes in the cell can damage it. Cells routinely repair this damage before making proteins or copying DNA for cell division. The repairs are remarkably accurate in normal cells but cancer cells make far more mistakes in fixing their DNA. Alan Tomkinson, PhD, University of New Mexico Professor of Internal Medicine and Associate Director of Basic Research at the UNM Cancer Center, wants to understand why and how these repair mechanisms go awry in cancer cells. This understanding could lead to new targets for cancer drugs. Dr. Tomkinson recently won a 4-year $1 million grant renewal to continue his 18-year research investigation on DNA ligases, the enzymes that repair DNA strands.

Scientists have discovered 100 million-year-old regions in the DNA of several plant species which could hold secrets about how specific genes are turned 'on' or 'off'.


These are differentiating mouse embryonic stem cells (green = mesoderm progenitor cells, red = endoderm progenitor cells). The microRNAs identified in this study block endoderm formation, while enhancing mesoderm formation.
An embryo is an amazing thing. From just one initial cell, an entire living, breathing body emerges, full of working cells and organs. It comes as no surprise that embryonic development is a very carefully orchestrated process—everything has to fall into the right place at the right time. Developmental and cell biologists study this very thing, unraveling the molecular cues that determine how we become human.


Ca2+ flux across the inner mitochondrial membrane regulates cell bioenergetics, cytoplasmic Ca2+ signals and activation of cell death pathways. Ca2+ uptake from the cytoplasm is driven by the electrochemical gradient...
Most healthy cells rely on a complicated process to produce the fuel ATP. Knowing how ATP is produced by the cell's energy storehouse – the mitochondria -- is important for understanding a cell's normal state, as well as what happens when things go wrong, for example in cancer, cardiovascular disease, neurodegeneration, and many rare disorders of the mitochondria.

Whether you are an apple tree or an antelope, survival depends on using your energy efficiently. In a difficult or dangerous situation, the key question is whether exerting effort — sending out roots in search of nutrients in a drought or running at top speed from a predator — will be worth the energy.

In a mouse model of multiple sclerosis (MS), researchers funded by the National Institutes of Health have developed innovative technology to selectively inhibit the part of the immune system responsible for attacking myelin—the insulating material that encases nerve fibers and facilitates electrical communication between brain cells.

The prevailing wisdom has been that every cell in the body contains identical DNA. However, a new study of stem cells derived from the skin has found that genetic variations are widespread in the body's tissues, a finding with profound implications for genetic screening, according to Yale School of Medicine researchers.

UC Irvine biologists have discovered that fats within cells store a class of proteins with potent antibacterial activity, revealing a previously unknown type of immune system response that targets and kills bacterial infections.

As they develop, vertebrate embryos form vertebrae in a sequential, time-controlled way. Scientists have determined previously that this process of body segmentation is controlled by a kind of "clock," regulated by the oscillating activity of certain genes within embryonic cells. But questions remain about how precisely this timing system works.

A new study demonstrates the dynamic role cilia play in guiding the migration of neurons in the embryonic brain. Cilia are tiny hair-like structures on the surfaces of cells, but here they are acting more like radio antennae.

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