Flying Mammals and a New Jumping Gene

Within our DNA are the remains of thousands, maybe millions, of genetic nomads. They once roamed free through the landscape of our genomes; now most are silenced and still, unable to move. These are the ‘jumping genes’, or ‘transposable elements’ to give them their proper name; curious stretches of mobile DNA. Almost 50% of our DNA is made of these remnants. We see them in virtually all organisms, from bacteria, insects and fish all the way through to us humans. In mammals the only active jumping genes we’ve seen are a type called retro-transposons, which scatter copies of themselves throughout genomes. Now a new DNA sequence for a different type of jumping gene, the first active example of its kind ever to be seen in a mammal, has been spotted jumping around in the genome of the brown bat.

Fighting fat with… fat?

What do explosives and weight loss have in common?* To find out we need to go back to World War One, to a munitions factory in France. People working with explosives were running high temperatures and losing weight. Some dangerously so. This was no fever, due to some viral or bacterial infection. It was due to a chemical they were using, similar in structure to TNT: dinitrophenol (DNP). Later, in the 1930s, DNP popped up again, this time marketed as a treatment for obesity. It failed due to its high toxicity. We now know how DNP causes these bizarre effects; it short-circuits a key process used by cells to store energy in chemical form, releasing it as heat instead. We’ve since discovered that this is a trick mammals are born to do to. A type of fat, called ‘brown adipose tissue’, or BAT, does the same trick as DNP, only ...(Read More)

A dried up celibate kleptomaniac

If there’s one thing that biologists agree on, it’s that sex is good. Really good*. Huge amounts of time and energy are invested in it. Well, alas, not so much in the act per se, as much as in finding a way to have sex; to tempt a mate or dispatch a rival. But is it really worth the ego busting knock-backs, the frustration, the time and energy? One quirky animal certainly doesn’t think so; it’s had a dry patch on a geological timescale. For the last 80 million years or so a small pond and fresh water dwelling animal called a bdelloid rotifer has done away with sex, and males, entirely. How has it managed for so long without sex? Simple. It steals.

My enemy’s enemy is my… enemy?

Like a kind of Russian doll infection, a prolific human parasite—responsible for almost 250 million infections annually—can itself harbour a parasite, a virus. You might reasonably feel a sense of something akin to schadenfreude; glad it’s getting a dose of its own medicine, so to speak… But you may be too hasty. The very presence of this virus—though it doesn’t infect human cells—in its parasite host could be making infections worse, or even stymying our attempts at  relieving the infection. The parasite in question, with around 3.7 million people infected in the US alone, is the most common protozoan infection in the industrialised world: Trichomonas vaginalis (TrV). It infects the human genitourinary tract of both men and women causing Trichomoniasis; in fact, it can only live in the human genitourinary tract (an ‘obligate human parasite’). Women are more likely to experience symptoms than men, and while generally mild,  it can be bad. Its ...(Read More)

Waking the (Tiny) giant…

Nestled safely away within your cells, among your DNA, lies something…foreign. An invader. Something you weren’t born with, hidden, evading your immune system and waiting to make its next strike: a ‘latent’ virus. In all probability, there are armies of different viruses performing this same trick throughout your body. Remaining silent; some of their own mysterious accord, others kept in check by your immune system or by random mutations, rendering them useless. Now researchers at The Ohio State University and the University of Oxford have worked out how some of these viruses can reactivate in healthy people, and once again go about their nefarious mindless deeds: hijacking our cells machinery, producing more of their own kind, and causing disease. An inefficient virus kills its host. A clever virus stays with it. — James Lovelock In healthy people latent viruses aren’t generally a problem, occasionally annoying, but rarely life threatening. However, ...(Read More)

Finding the un-natural in the lab…

Taming the power of the immune system in the lab wasn’t easy. For a start, it was a mystery how we have so many different antibodies, millions at any one time. But if it’s one gene per protein, and we only had something like 30,000 genes, how could we have millions of different antibodies? Understanding this problem was the key that unlocked one way to make antibodies against targets that we select. We can use them as tools in the lab, or to treat disease—therapeutic antibodies. Chances are you may know someone who has, or is, using them; if they have Crohn’s disease for example. Just finding antibodies that stick to a target—some unique bump, crevice or corner on a virus, for example—isn’t enough. The next step is to find out if they do something useful. They may stick but not prevent infection, or not activate some receptor on a ...(Read More)

Bioluminescent Proteins Shed Light On The Inner-life Of Neurons

It could almost be the negative of a view from a plane over a busy city at night. The lights of vehicles moving in and out, clusters of traffic; a city going about it’s business. But this city is a brain cell. A neuron. The roads are axons and dendrites; long slim projections that send (axons) and receive (dendrites) electrical impulses to and from the cell body. The lights aren’t cars, but proteins moving up and down the axons and dendrites. But they are definitely lights; of a sort. Much like post at a large sorting office, cellular proteins are sorted into groups, depending on where they are needed. This is done by the ‘golgi apparatus‘, the cells sorting office. Proteins are packaged into vesicles and are targeted to different areas, be it axon, dendrite, or elsewhere. The packages are attached to a group of proteins called Myosins that carry cargo along a kind of scaffold inside ...(Read More)