Bizarre experiments: Why did they do that?

From glowing cats to Teflon frogs, scientists carried out some bizarre experiments last year. Simon Usborne finds out what, exactly, they were trying to prove

Wednesday 02 January 2008 01:00 GMT

Why study kangaroo farts?

Until recently, we may have thought that the most interesting things about kangaroos were their mean left hooks and, in the case of Skippy the Bush Kangaroo, their ability to rescue lost children from the wilds of Australia.

But, thanks to research carried out in Queensland for the past four years, and released last month, the marsupial's cleverest trick is its ability to produce environmentally-friendly farts. Researchers have isolated the bacteria in the stomach lining of kangaroos that means their farts contain no methane, a greenhouse gas far more damaging than carbon dioxide.

The team, led by Dr Athol Klieve, believes that unlocking this secret could lead to the creation of more climate-friendly cattle. Between them, the flatulent farm animals produce so much methane that they account for 14 per cent of greenhouse gas emissions in Australia, second only to power stations. But if the kangaroo bacteria were added to cattle feed, the researchers hope they could create herds with much lower carbon footprints.

Scientists already know that kangaroo stomachs are more than just green. Instead of methane, they produce acetate, a chemical that improves digestion. Feed laced with kangaroo bacteria could give rise to livestock that is not only greener, but also faster-growing and more fertile.

Methane-busting feed supplements could be available commercially in as little as three years, but some scientists point to a more direct solution instead of slapping a hunk of beef or lamb on the barbie, why not kangaroo meat? This would help cap the marsupial population, which has reached plague proportions in parts of Australia, and connoisseurs say the meat is good. "It is also low in fat, high in protein and kangaroos are the ultimate free-range animal," says Peter Ampt of the University of New South Wales.

Why give frogs a Teflon coating?

You might expect frogs and Teflon to meet only in a French chef's frying pan. But in August, scientists at the University of Michigan revealed details of an experiment in which they created non-stick frog cells. Which, of course, raises the question: why?

Since the 1980s, scientists have been especially interested in frogs, among other animals, because their skin produces antimicrobial peptides (AMPs). These proteins are an incredibly useful way for the animals to fight infection AMPs are potent, broad-spectrum antibiotics. They are the immune system's first line of defence, combating microbes and viruses as they try to enter the body.

Scientists have tried to exploit these disease-fighting characteristics by putting AMPs in creams and other treatments used to fight infection in humans. But enzymes in the human skin stick to the AMPs, often rendering them useless, and increasing the concentration of AMPs often causes toxic side effects, such as killing red blood cells.

It was in an effort to combat this destructive stickiness that the scientists started to think about Teflon. Led by biological chemist Neil Marsh, the team considered what makes Teflon the plastic coating that stops your omelette sticking to the frying pan work so well.

"Teflon relies on a non-reactive fluorine coating to work," explains Marsh's colleague, Lindsey Gottler. "When we introduced fluorine to AMPs, we increased its stability, stopping them reacting with other proteins in the body."

Fortunately for frogs, none were required to create these non-stick AMPs. Marsh and his team used pexiganan, a synthetic copy of an AMP found in the Xenopus laevis frog. They then replaced certain amino acids in pexiganan with fluorinated alternatives, and called the new, non-stick peptide fluorogainin-1.

Marsh and his team hope the Teflon-tipped AMPs will help doctors to fight bacteria that are becoming increasingly resistant to conventional treatments. They could appear in improved creams designed to combat skin ulcers in diabetes patients, eye infections, or even the hospital bug MRSA.

What's the point of a glow-in-the-dark cat?

In 2006 in Taipei, scientists injected a protein taken from jellyfish into a pig embryo to create an eerie-looking luminous-green pig. This year, scientists in South Korea cloned a cat that glows red when exposed to ultraviolet light. Why this apparent obsession among the world's great scientists with phosphorescing animals?

In the case of the scientists who cloned three felines (white Turkish angoras, to be precise) in January and February last year, the aim was not to reduce night-time road accidents, but to develop treatments for genetic diseases in humans.

A team led by Kong Il-keun at Gyeongsang National University used a virus to modify the genes of a mother cat's skin cells, making them fluorescent. Kong then transplanted these cells into the cat's ova, which were in turn implanted into the womb of a donor cat.

But the glowing offspring of this test-tube tabby are no more useful to mankind than your auntie's moggy; the red glow is merely a marketing exercise designed to draw attention to the team's work.

"The technology used to produce cloned cats with manipulated genes can be applied to clone animals suffering from the same diseases as humans," Kong explained at a press conference in December. Scientists hope these cloned cats (and other animals) will serve as sophisticated guinea pigs, speeding up the development of drugs and allowing scientists to conduct tests they could not carry out on human patients.

Why give worms antidepressants?

They burrow, they eat, they breed, they die. A worm's lot is simple and, apart from the odd attack from birds, fairly anxiety-free or so you would think. So why did a group of scientists at the Fred Hutchinson Cancer Research Centre in Seattle, who published the results of their experiments in the journal Nature in November, treat them with antidepressants?

In fact, it was not intended to treat them for depression at all. Michael Petrascheck and his team wanted to find out how they could make Caenorhabditis elegans (roundworms) live longer. Measuring only one millimetre long, the worms have an average lifespan of three weeks.

And it wasn't just antidepressants that Petrascheck used. He treated a batch of roundworms with 80,000 randomly selected drug compounds, to see which, if any, would make the animals live longer. A handful of drugs made a significant difference and one an antidepressant called mianserin succeeded in extending the worms' lifespan by 30 per cent, adding almost a week to the animals' lives. Mianserin achieves this by tricking the worm into thinking it is starving, but without causing malnutrition. But more research is needed as it is not yet understood why this leads to a longer life.

So has Petrascheck begun to unearth the elixir of youth? "It's a stretch to conclude that if worms live longer humans will, too," he says, "but we hope this research will tell us more about age-related diseases. Could these drugs also alleviate age-related diseases? And, if so, how does it work?"

Why map the genome for the fungus that causes Dandruff?

Scientists have decoded the genetic building blocks of organisms ranging from yeast and rice to humans. But the fungus that causes dandruff? Surely we don't want to decode that one.

The facilities of one of the world's most advanced science labs were used to sequence the genetic code of Malassezia globosa, the fungus that causes inconvenient flurries of dead skin to dust the shoulders of more than half of humans.

"The only way to control dandruff is to make shampoos that kill the fungus," explains Thomas Dawson from P&G Beauty's Miami Valley Innovation Centre in Ohio, "But this is often inefficient, because the fungi are so much part of our scalps that they are sometimes immune to the shampoos."

To understand how to combat M globosa, you first need to know exactly how it works. And there's no better way of getting to know an organism than to unlock the secrets of its DNA. So, Dawson and his team, who reported their work in Proceedings of the National Academy of Sciences in November, grew 10 litres of the fungus enough to give dandruff to 10 million people and sequenced its genes.

"We now have the ability to study the interaction between the fungus and the scalp," says Dawson, whose team established that M globosa can excrete up to 50 separate enzymes that can cause dandruff. "We hope to create a shampoo with ingredients that would inhibit specific pathways in the fungus, or enhance specific pathways in the human, to restore the natural balance found in people who don't get dandruff."

Why produce robotic snot?

We know that it produces excruciating photos of nose-picking politicians, and that it adds to the misery of millions of cold and flu victims, but did you know that olfactory mucus also has a key function: it enhances our sense of smell.

Mucus, it turns out, separates the myriad chemical compounds that make up the smell of, say, frying onions. These compounds travel through the mucus at different speeds, hitting our scent receptors at different times. By dissecting and separating smells in this way, mucus allows our brains to identify scents more quickly and accurately.

It was with this in mind that, in April, Professor Julian Gardner of the University of Warwick started to improve his electronic noses, which have been used (without mucus) for years, in everything from the production of artificial fragrances to quality control in crisp factories.

"We built a polymer that replicates the function of snot," says Gardner. "It's not green but it has the same consistency as human snot and, applied to our sensors, means our artificial noses are at least five times better than those without snot."

Join our commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies


Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged inPlease refresh your browser to be logged in