Weekend Herald

Weird Science

- with Herald science writer Jamie Morton: @jamienzher­ald

Can we accurately forecast death

Kiwi scientists may have found a way to accurately calculate death days before it happens — at least in the humble fruit fly.

University of Auckland researcher Jia Zhao has been using the minuscule flies to research the circadian clock, and has discovered a molecular marker that can help forecast the animal’s death several days before.

The circadian clock, which generates the daily rhythms in most organisms, is affected by time and diminishes with advancing age.

“We are interested in the circadian clock, which you and I and every animal has,” said Zhao’s supervisor, Dr James Cheeseman.

“It controls everything from behaviour to physiology. The primary implicatio­n in this study is that death, at least in flies, can be reliably predicted in clock gene expression.

“We used the flies as a model because we can monitor the circadian clock rhythms in the living flies right down to cycling of individual clock genes.” The study looked specifical­ly at two circadian clock genes, which have similar counterpar­ts in humans, and how they change in the days immediatel­y preceding death.

The fruit fly was chosen because it had a short life cycle and shared a similar circadian clock to humans.

While breakdown of the clock in behaviour had been observed before, no one has tested clock gene expression.

When one of the two genes started to increase, it began to lose rhythmicit­y — signalling that the fly was going to die in four days.

“We hypothesis­e that it’s the breakdown in communicat­ion between the peripheral clock cells which causes this,” Zhao said.

“The flies don’t have to be old to show this pattern, it’s a marker in young flies as well as old.” More importantl­y, the fly provided a model for the ageing of circadian clocks more generally — and had implicatio­ns for other animals and humans.

Tarantula venom to fight kid’s disease

Aussie scientists think they’ve found a secret weapon to use against a childhood disease — inside the venom of a tarantula.

Dravet syndrome is a catastroph­ic epilepsy affecting young children before their first birthday. Children live with a range of very serious symptoms including intellectu­al disabiliti­es and multiple daily seizures, and the disease can result in early death.

Now, using a key ingredient isolated from tarantula venom, University of Queensland scientists have discovered an effective treatment.

Dravet syndrome is caused by a mutation in a gene that produces protein critical for calming electrical activity in the brain.

Patients with Dravet syndrome only have half the normal amount of this protein, meaning the brain is overactive, which results in seizures and the other features of Dravet syndrome.

“We reasoned that if we could just make the remaining protein work harder, it would effectivel­y pick up the slack — much like a cyclist on a tandem bicycle can help her exhausted passenger by pedalling harder to maintain speed,” Professor Steven Petrou said.

Before treatment, young Dravet mice displayed reduced activity in a specific type of brain cell whose job it is to reduce overall brain activity.

“After applying the compound from the spider venom to nerve cells from the brains of Dravet mice we saw their activity immediatel­y return to normal, said Petrou.

“Infusion into the brains of the Dravet mice not only restored normal brain function within minutes but over three days, we noted a dramatic reduction in seizures in the mice and increased survival. Every single untreated mouse died.”

The team’s results show it may be possible to treat this previously intractabl­e epilepsy by directly targeting the faulty gene.

Don’t eat this cheese

Speaking of ageing, scientists have discovered what might be the world’s most matured block of cheese.

The tomb of Ptahmes, mayor of Memphis in Egypt during the 13th century BC, was initially unearthed in 1885. After being lost again under drifting sands, it was rediscover­ed in 2010, and archaeolog­ists found broken jars at the site a few years later. One jar contained a solidified whitish mass, as well as canvas fabric that might have covered the jar or been used to preserve its contents.

Analysis later revealed it to be a dairy product made from cow’s milk and sheep or goat milk.

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