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What's been going on this month

Why Dunce, the mutant fly gene, matters

WE GENETICISTS are a funny bunch. And fly geneticists are the funniest of them all. They love to give witty names to genes, and looking through the Drosophila fly gene list you’ll encounter maggie (characterised by arrested development, like the Simpsons character), lilliputian (small flies), tinman (with no heart), and methuselah (long lived). By contrast, yeast genes have boring names like PHM7 and YOL083W. So, when fly geneticists first discovered a mutant strain that couldn’t learn, they called it (and the associated gene) dunce.

We don’t think of flies learning or having memories, but they do. What’s more, thanks to our common evolutionary origins (albeit some 900 million years ago) the underlying genetic basis is the same in flies and in humans. This means that research into these tiny flies can teach us about normal learning and memory in humans, as well as medically relevant conditions, including Alzheimer’s.

Although it doesn’t feel intuitive, memories are physical entities within our brain, not misty notions floating in the ether. Recent work has revealed the underlying molecular basis of memory formation in fly brains, a body of knowledge that continues to grow. We now know that the formation of medium-term memories (lasting up to two days) requires that new proteins are produced from existing “messages” already lying in wait in the cell (technically called “messenger RNA”, produced from genes). However, the formation of long-term memory (potentially lasting a whole lifetime) requires particular genes to be turned on to produce new messages, which then go on to produce proteins and thus memories. Critically, for long-term memory formation, exposure to the stimulus (whatever it is you are to learn) must be repeated and must be spaced out in time. Which sounds exactly like exam revision, doesn’t it?

Apart from dunce, there are many other fly-learning mutants including ignorant, crammer, and leonardo. I know which one I’d rather be.

Aoife McLysaght is a geneticist in Trinity College Dublin

Thunder thighs

Remains of a strong-legged dinosaur have turned up in Utah, in the United States. The long-necked Brontomerus mcintoshi has been nicknamed “thunder thighs” because of its muscular legs.

Scientists in the US and at University College London who analysed the fossils think the animals, which lived about 110 million years ago, may have used their powerful limbs to kick away predators or to get around over rough, hilly ground.

METEORITE ROW

This month a NASA scientist claimed to have found micro-fossils in meteorite samples, suggesting that life forms could have hitchhiked to Earth from space. But while news reports whizzed the claims around the world, many other scientists were less impressed and highly sceptical of the findings. The journal in which the study was published promotes the idea of life in outer space.

WALKING INSIDE THE HUMAN BRAIN

Imagine walking through a human brain, being surrounded by tangles of fizzling and firing neurons and lulled by the swishing sounds of life.

Okay, it’s not likely to happen for real, but if you want a great pretend version, you can get it at the Brain exhibition at the American Museum of Natural History in Manhattan, New York.

When you emerge from the weird darkness of that sparky tunnel there’s plenty more to excite at the exhibition, including tests to see how well you can mimic another language, details of implants and technologies to help people with injured brains and models you can build to see how our more “primitive” brain sections are encased within the outer part that allows us to think like humans. And if you can’t get to New York before the exhibition closes on August 15th, you can see it online at amnh.org

GOING UP, COMING DOWN

The space shuttle Discoverymade its last trip into space this month.

It brought equipment, including a humanoid robot, up to the International Space Station, which is orbiting Earth (sometimes you can see it in the night sky over Ireland).

Discovery landed again safely last week, completing its 39th mission.

Over its lifespan it has clocked up 365 days in space, orbited Earth 5,830 times and traveled 148,221,675 miles.

Another Nasa mission didn’t go so well though. The Glory satellite was meant to orbit Earth and collect data about climate. But things didn’t go to plan just after the launch this month and the satellite never made it into orbit. Instead, Glory fell down to the South Pacific.

HUMANS DITCHED DNA

Sometimes the DNA you don’t have is important. A new study by scientists in California compared DNA from humans and chimps, and found more than 500 stretches that are in chimps and other mammals, but not in us. Almost all of the “missing” DNA stretches are not genes themselves but they are important for regulating genes.

The researchers, who published their findings in the journal Nature, reckon that losing chunks of DNA could have helped humans to evolve particular traits that other animals don’t have.

TWO TRUNKS BETTER THAN ONE

Elephants appear to co-operate when faced with a task where two trunks are better than one, according to new findings.

The study, carried out with Asian elephants, saw the pairs of animals succesfully carry out tests originally designed for monkeys and apes, where each partner has to pull on a separate rope to receive food.

The elephants even twigged that they should wait if their partner wasn’t there yet, write the study authors in Proceedings of the National Academy of Sciences.

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