20 May 2013 Sweet Discovery Estimated to affect over 170 million people worldwide, diabetes is a major modern-day health concern. Caused by failure to regulate blood sugar, this disease arises because of defects in the production of insulin, a hormone that acts to decrease the levels of glucose in the blood, or in the way other tissues respond to it. Researchers have recently identified a hormone, named betatrophin, which is secreted by liver and fat tissue, and stimulates duplication of insulin-producing cells in the pancreas. Raising the levels of betatrophin makes the pancreatic cells replicate faster, and having more of these cells means that more insulin is made. In the mouse pancreas pictured, the pink spots identify a protein characteristic of replication, thus revealing that some of the cells that produce insulin (stained green) are duplicating. Also found in humans, betatrophin could provide potential alternatives to insulin injections in the treatment of diabetes. Written by Emmanuelle Briolat — Douglas Melton Harvard University, USA Copyright Elsevier 2013 Published in Cell 2013
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20 May 2013

Sweet Discovery

Estimated to affect over 170 million people worldwide, diabetes is a major modern-day health concern. Caused by failure to regulate blood sugar, this disease arises because of defects in the production of insulin, a hormone that acts to decrease the levels of glucose in the blood, or in the way other tissues respond to it. Researchers have recently identified a hormone, named betatrophin, which is secreted by liver and fat tissue, and stimulates duplication of insulin-producing cells in the pancreas. Raising the levels of betatrophin makes the pancreatic cells replicate faster, and having more of these cells means that more insulin is made. In the mouse pancreas pictured, the pink spots identify a protein characteristic of replication, thus revealing that some of the cells that produce insulin (stained green) are duplicating. Also found in humans, betatrophin could provide potential alternatives to insulin injections in the treatment of diabetes.

Written by Emmanuelle Briolat

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Published in Cell 2013

Source: bpod.mrc.ac.uk

23 April 2013 Enhancing Expression Multicellular organisms contain a cornucopia of different cell types. Each has specific characteristics and functions, even though almost all contain the same genetic information. Such diversity is possible because each cell type expresses a unique subset of the genes encoded in DNA, a process controlled by non-coding sections of the genome called enhancers. Researchers don’t know much about them yet, but have recently come up with a way to identify the DNA sequences that function as enhancers and measure their activity in specific cells. Pictured are fruit fly ovary cells used to validate the method, with DNA stained fluorescent blue, and green representing the strength of enhancer activity. Scientists hope to use the technique to map the regulatory parts of the human genome and study how they’re involved in turning genes on and off during normal development and disease. Written by Daniel Cossins — Arnold Cosmas Research Institute of Molecular Pathology, Austria Reprinted with permission from AAAS. Published in Science 339(6123): 1074-1077
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23 April 2013

Enhancing Expression

Multicellular organisms contain a cornucopia of different cell types. Each has specific characteristics and functions, even though almost all contain the same genetic information. Such diversity is possible because each cell type expresses a unique subset of the genes encoded in DNA, a process controlled by non-coding sections of the genome called enhancers. Researchers don’t know much about them yet, but have recently come up with a way to identify the DNA sequences that function as enhancers and measure their activity in specific cells. Pictured are fruit fly ovary cells used to validate the method, with DNA stained fluorescent blue, and green representing the strength of enhancer activity. Scientists hope to use the technique to map the regulatory parts of the human genome and study how they’re involved in turning genes on and off during normal development and disease.

Written by Daniel Cossins

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Bite the Bullet They look like man-made bullets and these naturally-occurring viruses can be just as deadly. Vesicular stomatitis (pictured) belongs to a family of viruses called rhabdoviruses which self-assemble, forming round-tipped ‘shells’ around a payload of viral material. Colliding with a vulnerable target cell, these shells burst open, rearranging to protect and stabilise the viral material as it leaks out. Often 150,000 times smaller than a 9mm bullet, rhabdoviruses can quickly replicate and shoot from cell to cell to spread their infection. They do the most immediate damage, however, when lodged deep within a tissue. A bite from an infected dog might take viral ‘bullets’ loaded with Rabies, another rhabdovirus, deep into a muscle, far away from our immune defences and, unless treated quickly, nearly always fatal. Written by John Ankers — Irina Gutsche Unit of Virus Host Cell Interactions, Grenoble, France Reprinted by permission from Macmillan Publishers Ltd: Nature Communications Copyright 2013 Published in Nature Communications 4: 1429
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Bite the Bullet

They look like man-made bullets and these naturally-occurring viruses can be just as deadly. Vesicular stomatitis (pictured) belongs to a family of viruses called rhabdoviruses which self-assemble, forming round-tipped ‘shells’ around a payload of viral material. Colliding with a vulnerable target cell, these shells burst open, rearranging to protect and stabilise the viral material as it leaks out. Often 150,000 times smaller than a 9mm bullet, rhabdoviruses can quickly replicate and shoot from cell to cell to spread their infection. They do the most immediate damage, however, when lodged deep within a tissue. A bite from an infected dog might take viral ‘bullets’ loaded with Rabies, another rhabdovirus, deep into a muscle, far away from our immune defences and, unless treated quickly, nearly always fatal.

Written by John Ankers

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Source: bpod.mrc.ac.uk

A Leggy Model Deep within a mouse leg bone – shown here in cross-section – something is going wrong. Cells are multiplying out of control in the bone marrow, creating a type of cancer called myeloma (stained bluey-purple). Although it’s not a very common cancer, myeloma can be difficult to treat successfully and fewer than four in ten patients currently survive for more than five years. One major problem holding back the development of better treatments is the social nature of the cancer cells. They need to interact with other cells in the bone marrow to grow properly – something that’s hard to recreate in lonely plastic dishes in the lab. By studying mice that have had myeloma cells transplanted into their leg bone marrow, researchers can get a more realistic view of how the cancer responds to drugs in a real life situation, helping them to pinpoint the most effective future treatments. Written by Kat Arney — Faith Davies The Institute of Cancer Research, UK Originally published under a Creative Commons Attribution license Published in PLoS ONE 8(2): e57641
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A Leggy Model

Deep within a mouse leg bone – shown here in cross-section – something is going wrong. Cells are multiplying out of control in the bone marrow, creating a type of cancer called myeloma (stained bluey-purple). Although it’s not a very common cancer, myeloma can be difficult to treat successfully and fewer than four in ten patients currently survive for more than five years. One major problem holding back the development of better treatments is the social nature of the cancer cells. They need to interact with other cells in the bone marrow to grow properly – something that’s hard to recreate in lonely plastic dishes in the lab. By studying mice that have had myeloma cells transplanted into their leg bone marrow, researchers can get a more realistic view of how the cancer responds to drugs in a real life situation, helping them to pinpoint the most effective future treatments.

Written by Kat Arney

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Source: bpod.mrc.ac.uk

Funny Smells Even flies can be put off rotten food by its yucky smell. Scientists have discovered that fruit flies have special sensory cells to detect geosmin, a chemical produced by bacteria. This means they can avoid colonies of harmful microbes when feasting on yeast – their favourite food – on the surface of fermenting fruit. Flies don’t have noses but odour-sensing cells on their antennae and mouthparts (so they can’t join in the fund-raising stunts of today’s Red Nose Day in the UK). Fruit flies are used extensively for research into the role that genes play in the animal sense of smell, known as the olfactory system. Pictured is a fruit fly’s head with dots of colour marking different types of odour-sensing receptors, with superimposed letters denoting the gene sequences that keep them active. Written by Mick Warwicker — Rachel Jones Originally published under a Creative Commons Attribution license Published in PLoS Biology 6(5): e134
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Funny Smells

Even flies can be put off rotten food by its yucky smell. Scientists have discovered that fruit flies have special sensory cells to detect geosmin, a chemical produced by bacteria. This means they can avoid colonies of harmful microbes when feasting on yeast – their favourite food – on the surface of fermenting fruit. Flies don’t have noses but odour-sensing cells on their antennae and mouthparts (so they can’t join in the fund-raising stunts of today’s Red Nose Day in the UK). Fruit flies are used extensively for research into the role that genes play in the animal sense of smell, known as the olfactory system. Pictured is a fruit fly’s head with dots of colour marking different types of odour-sensing receptors, with superimposed letters denoting the gene sequences that keep them active.

Written by Mick Warwicker

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Source: bpod.mrc.ac.uk

Food for Thought Brains burn more energy than any other organ to produce and drive electrical signals along the filament-like brain cells that control everything from our breathing to our thoughts. In fact, neuroscientists estimate that 20% of our total energy budget is used just to keep our brains firing. And burning all that energy means brain cells need oxygen, and lots of it. A vast network of blood vessels (around 100,000 miles long) irrigates every nook of our brain ensuring it’s never starved of oxygen or nutrients. But there is still much to be learned about how vessels grow and form networks – a process called angiogenesis. Studying mouse brain (pictured), researchers have identified over 60 genes that could act as switches controlling the growth of vessels. In future, this could help stroke patients heal, or reversely, could be used to kill off brain tumours by stemming their blood supply. Written by Tristan Farrow — Ayşe N Başak, Boğaziçi University, Turkey Türker Kılıç, Marmara University, Turkey Originally published under Creative Commons Attribution License (CC-BY 2.0) Published in Vascular Cell 4:16
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Food for Thought

Brains burn more energy than any other organ to produce and drive electrical signals along the filament-like brain cells that control everything from our breathing to our thoughts. In fact, neuroscientists estimate that 20% of our total energy budget is used just to keep our brains firing. And burning all that energy means brain cells need oxygen, and lots of it. A vast network of blood vessels (around 100,000 miles long) irrigates every nook of our brain ensuring it’s never starved of oxygen or nutrients. But there is still much to be learned about how vessels grow and form networks – a process called angiogenesis. Studying mouse brain (pictured), researchers have identified over 60 genes that could act as switches controlling the growth of vessels. In future, this could help stroke patients heal, or reversely, could be used to kill off brain tumours by stemming their blood supply.

Written by Tristan Farrow

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Source: bpod.mrc.ac.uk

How Flies Feel When it comes to the sense of touch, our bodies are capable of detecting the lightest brush of a feather against skin, or a haymaker thump to the gut. But how do our nerves detect and distinguish such forces? What’s behind this incredible range of sensory detection? Scientists are getting closer to answering these questions, at least in fruit flies. They have identified cells that respond to certain pain stimuli and more recently they have also discovered that the neurons [nerve cells] pictured (purple) are responsible for detecting gentle touch. These cells have masses of protrusions called sensory filopodia packed with specialized ion channels (white), which activate the cell in response to gentle mechanical forces. Disturbances in either the channels or the protrusions render fruit fly larvae incapable of reacting to being tickled with an eyelash – a standard albeit quirky method of testing touch in flies. Written by Ruth Williams — W. Daniel Tracey Duke University Medical Center, USA Copyright Elsevier 2012 Published in Current Biology 103(8):1666–1671
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How Flies Feel

When it comes to the sense of touch, our bodies are capable of detecting the lightest brush of a feather against skin, or a haymaker thump to the gut. But how do our nerves detect and distinguish such forces? What’s behind this incredible range of sensory detection? Scientists are getting closer to answering these questions, at least in fruit flies. They have identified cells that respond to certain pain stimuli and more recently they have also discovered that the neurons [nerve cells] pictured (purple) are responsible for detecting gentle touch. These cells have masses of protrusions called sensory filopodia packed with specialized ion channels (white), which activate the cell in response to gentle mechanical forces. Disturbances in either the channels or the protrusions render fruit fly larvae incapable of reacting to being tickled with an eyelash – a standard albeit quirky method of testing touch in flies.

Written by Ruth Williams

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Published in Current Biology 103(8):16661671

Source: bpod.mrc.ac.uk

Vicious Circles A third of the world’s population has the parasite Toxoplasma gondii (T. gondii) living inside them. Infestation by these simple organisms (usually from eating infected meat) can cause serious problems during pregnancy. Here T. gondii has been genetically-modified to glow in a dish, allowing us to see how they might travel around inside our bodies. Their swirling traces were captured by microscope, similar to how a night-time video captures the trail of light from the tip of a sparkler. While it may look a little chaotic, this picture shows three distinct types of movement. The parasites (each cell is a white dot 400 times smaller than a glowing match head) are either spiralling, looping-the-loop, or twirling in star-like patterns. However pretty they are, watching these parasitic patterns could also guide the design of more effective drugs to stop future invasions in their elegant tracks. Written by John Ankers — James McCoy, Christopher Tonkin The Walter and Eliza Hall Institute of Medical Research, Australia Originally published under a Creative Commons Attribution license Published in PLOS Pathogens 8(12): e1003066
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Vicious Circles

A third of the world’s population has the parasite Toxoplasma gondii (T. gondii) living inside them. Infestation by these simple organisms (usually from eating infected meat) can cause serious problems during pregnancy. Here T. gondii has been genetically-modified to glow in a dish, allowing us to see how they might travel around inside our bodies. Their swirling traces were captured by microscope, similar to how a night-time video captures the trail of light from the tip of a sparkler. While it may look a little chaotic, this picture shows three distinct types of movement. The parasites (each cell is a white dot 400 times smaller than a glowing match head) are either spiralling, looping-the-loop, or twirling in star-like patterns. However pretty they are, watching these parasitic patterns could also guide the design of more effective drugs to stop future invasions in their elegant tracks.

Written by John Ankers

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Source: bpod.mrc.ac.uk

Controlling Constriction Our arteries and arterioles [small arteries] must keep blood flowing to the tissues at all times, ensuring a consistent oxygen supply. One way they achieve this is to control their diameters. Narrowing (vasoconstriction) or expanding (vasodilation) the vessels enables blood to flow more slowly or faster. To control constriction endothelial cells, which line the blood vessels, communicate with surrounding smooth muscle cells, telling them to either relax or tense up. The two cells types are separated by an elastic layer of cells (shown in white, with blue nuclei), but holes in the layer allow the endothelial cells to reach through with finger-like projections. Scientists now know that these projections contain particular proteins (yellow) that can detect the blood pressure inside the vessel, convey that information to the muscle cells, and ultimately keep blood flowing to where it’s needed. Written by Ruth Williams — Christopher Garland Ray Mitchell Dept of Pharmacology, University of Oxford Published in PNAS 109(44): 18174-18179 
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Controlling Constriction

Our arteries and arterioles [small arteries] must keep blood flowing to the tissues at all times, ensuring a consistent oxygen supply. One way they achieve this is to control their diameters. Narrowing (vasoconstriction) or expanding (vasodilation) the vessels enables blood to flow more slowly or faster. To control constriction endothelial cells, which line the blood vessels, communicate with surrounding smooth muscle cells, telling them to either relax or tense up. The two cells types are separated by an elastic layer of cells (shown in white, with blue nuclei), but holes in the layer allow the endothelial cells to reach through with finger-like projections. Scientists now know that these projections contain particular proteins (yellow) that can detect the blood pressure inside the vessel, convey that information to the muscle cells, and ultimately keep blood flowing to where it’s needed.

Written by Ruth Williams

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Source: bpod.mrc.ac.uk

Slices of Life To see how genetic mutations affect the development and physiology of fruit flies (Drosophila), scientists can now use ultramicroscopy – a technique that produces ultra-detailed 3D images of a fly’s insides. First, water in the specimen is replaced with a solution that allows laser beams to better penetrate the tissue. Then an extremely thin, flat laser beam is shone horizontally through the fly layer by layer. As the laser passes through the body, it makes each thin slice of tissue fluoresce, and the light is captured in a microscopic snapshot each time. Finally, the images are digitally stitched together to create a 3D model. This cross-sectional plane (pictured) shows tissues inside a fly’s head, including its eye. Each scan takes only 30 minutes, so scientists can quickly image lots of specimens. The technique is also used to study brain cell networks in mice, and to investigate cancerous tumours in humans. Written by Daniel Cossins — Hans Dodt & Saideh Saghafi Vienna University of Technology
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Slices of Life

To see how genetic mutations affect the development and physiology of fruit flies (Drosophila), scientists can now use ultramicroscopy – a technique that produces ultra-detailed 3D images of a fly’s insides. First, water in the specimen is replaced with a solution that allows laser beams to better penetrate the tissue. Then an extremely thin, flat laser beam is shone horizontally through the fly layer by layer. As the laser passes through the body, it makes each thin slice of tissue fluoresce, and the light is captured in a microscopic snapshot each time. Finally, the images are digitally stitched together to create a 3D model. This cross-sectional plane (pictured) shows tissues inside a fly’s head, including its eye. Each scan takes only 30 minutes, so scientists can quickly image lots of specimens. The technique is also used to study brain cell networks in mice, and to investigate cancerous tumours in humans.

Written by Daniel Cossins

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Source: bpod.mrc.ac.uk