Australian scientists hope to bring extinct frog back to life

In a process that sounds like Jurassic Park but is closer to the cloned sheep Dolly, Australian scientists are bringing an extinct amphibian back to life.

The gastric-brooding frog, which swallowed its eggs, grew its young in its stomach and gave birth through its mouth, became extinct about 30 years ago.

But scientists working on the “Lazarus project” have successfully reactivated its DNA and produced an embryo.

Prof Mike Archer of Sydney’s University of New South Wales said the gastric-brooding frog was an extraordinary creature.

“In the stomach these eggs went on to develop into tadpoles and the tadpoles then went on to develop into little frogs,” he told ABC radio.

“And like any pregnant mum, when you have little babies rattling away in your stomach saying, ‘let me out’, she would then open her mouth and out would pop little frogs.

“The first people that saw that were aghast. By the time anybody got excited about it, suddenly it was extinct.”

The team, which also includes researchers from the University of Newcastle north of Sydney, found some gastric-brooding frog carcasses stored in a deep freezer and were able to recover tissue.

Using a technique called somatic cell nuclear transfer, they implanted the dead cell nucleus from the extinct species into an egg from another frog species. From this, the scientists created an embryo.

“There was one day in the laboratory that was so exciting when all of a sudden the egg from this living species that had had one of these extinct frogs’ nuclei inserted into it started to divide, and then divide again,” Prof Archer said. “We were holding our breath and then it just kept going . . . It went on to develop an embryo.”

Though the embryo has so far only survived 36 hours, the Lazarus project team is confident that producing a tadpole is the next step.

“We are in a research zone beyond where anyone else has been before and there’s no signpost,” Prof Archer said.

Larvae turn ladybugs into Zombies

Scientists at the University of Montreal have discovered a type of larva that turns ladybird beetles into the living dead of sorts, using them for food and shelter in the process. 

The larvae of the Dinocampus coccineilae parasitic wasp colonize and consume the ladybugs while they are still alive, the scientists observed. The larva is laid as an egg in the soft interior ofthe ladybug, where it can grow without beng disturbed by its natural predators. After some 20 days, the larva breaks out ofthe ladybug's body and spins a cocoonbetween the beet|e's legs.This nearly paralyzes the ladybug so that it can barely move and has no choice but to protect the pupa—stage wasp with its body.

 

The larva continues to feed on the ladybug, and it is able to survive the feeding. The larva benefits from its host's life up to the very last minute:The living ladybug occasionally jerks, which is likely enough movement to keep the |arva’s enemies at bay. When the larva is ready to leave the pupa, it releases its host, which — to the scientists‘ surprise — sometimes has sufficient energy to resume its pre-occupation life; this phenomenon was observed in 25 percent of cases.

Twin Earth Discovered, KOI 172.02, Most Earth-Like Planet Yet Found

By Nathan

The most Earth-like planet yet found has just been discovered by the Kepler space probe. The newly discovered exoplanet is actually about 1.5 times bigger than Earth, so it’s known as a ‘super-Earth’. The planet, KOI (Kepler Object of Interest) 172.02, is following an orbit that is well within the habitable zone of a star that is rather similar to our Sun. This leaves open the possibility that the planet could feature liquid water and potentially oceans on its surface. 

KOI 172.02 orbits at a distance of around 0.75 astronomical units from its star, meaning that it is about 3/4 the distance from its star that the Earth is from the sun. Specifically, this means that KOI-172.02 orbits around 70 million miles from its star rather than the 93 million miles that the Earth orbits from the Sun. And as a result completes an orbit around its star in 242 Earth days. 

“Launched in 2009, the Kepler space telescope orbits the sun every 371 days. As it travels, Kepler keeps itself pointed at a single patch of sky. Sensors monitor the brightness of 150,000 stars simultaneously, looking for telltale drops in intensity that could indicate orbiting planets.”

“At the heart of the telescope is an array of 42 camera sensors specifically designed to detect planets passing in front of their stars”

“Kepler’s planet search is conducted in a narrow wedge-shaped volume of space that stretches out ahead of us as we orbit the galaxy. Stars in the search volume are therefore at about the same distance from the center of the galaxy as the Earth.”

Researchers from NASA note that the planet would be a prime candidate to explore in the search for extraterrestrial life. Though other, more strange seeming planets, such as the recently discovered rogue planet that is only 100 light years away, could also potentially host life.

An Earth analog, or Earth-like planet, is a theorezied type of exoplanet, or moon, that features conditions very similar to the Earth.

“The possibility is of particular interest to humans as it is easily inferred that the more similar a planet is to Earth, the more likely it is of sustaining Earth-like complex extraterrestrial life and, more importantly, civilization. As such it has long been speculated and the subject expressed in science, philosophy, science fiction and popular culture. Advocates of space colonization have long sought an Earth Analog as a ‘second home’ while advocates for space and survival would regard such a planet as a potential ‘new home’.”

“Before the scientific search for and study of extrasolar planets, the possibility was argued through philosophy and science fiction. The Mediocrity principle suggests that planets like the Earth should be common in an infinite universe, while the Rare Earth hypothesis suggests that they are extremely rare. Philosophers have pointed out that the size of the universe is such that a near identical planet must exist somewhere, such theories include the philosophy of Multiverse and the Twin Earth thought experiment.”

“Some scientific theories speculate that Earth analogs may have existed in our Solar System in the past. In the future, technology may be used by humans to artificially produce an Earth analog. In theory, terraforming, virtual reality or simulated reality could potentially create such a world. Multiverse theory suggests that an Earth analog could exist in another universe or even be another version of the Earth itself in a parallel universe.”

“Technological advances in extrasolar planet detection are rapidly refining the probabilities of a real discovery, not just in this universe, but in the present Milky Way galaxy, though distribution and attributes are still very much unknown. Different studies on the frequency of Earth-like planets in the Milky Way have resulted in estimation varying from one (ie the Earth) to hundreds of billions. Current calculations tend to indicate that they may be relatively common in the universe.”

“The more recent serious scientific findings have greatly influenced the scope of the fields of astrobiology, models of planetary habitability and Search for Extraterrestrial Intelligence. NASA and the SETI Institute have proposed categorising the increasing number of Earth-like planets found using a measure called the Earth Similarity Index based on mass, radius and temperature. According to this measure, the planet currently thought to be most similar to Earth is Gliese 667C c.”

Source: Space and Wikipedia

Image Credits: NASA

The brain circuit that makes it hard for obese people to lose weight

Researchers in Australia explain why when obese people diet, they end up losing less weight.

Imagine you are driving a car, and the harder you press on the accelerator, the harder an invisible foot presses on the brake. That’s what happens when obese people diet – the less food they eat, the less energy they burn, and the less weight they lose.

While this is a known phenomenon, scientists at Sydney’s Garvan Institute of Medical Research and the University of New South Wales (UNSW) have pinpointed the exact brain circuitry behind it using various mouse models. 

In the journal Cell Metabolism, Dr. Shu Lin, Dr. Yanchuan Shi, and Professor Herbert Herzog and his team show that the neurotransmitter Neuropeptide Y (NPY), known for stimulating appetite, also plays a major role in controlling whether the body burns or conserves energy.

“This study is the first to identify the neurotransmitters and neural pathways that carry signals generated by NPY in the brain to brown fat cells in the body. It is also the first to show a direct connection between Arc NPY, the sympathetic nervous system and the control of energy expenditure,” said Herzog.

The researchers found that NPY – produced in a particular region of the brain called the arcuate nucleus (Arc) of the hypothalamus – inhibits the activation of ‘brown fat,’ one of the primary tissues where the body generates heat.

While NPY also influences other aspects of the sympathetic nervous system such as heart rate and gut function, its control of heat generation through brown fat seems to be the most critical factor in the control of energy expenditure.

“When you don’t eat, or dramatically curtail your calorie intake, levels of NPY rise sharply. High levels of NPY signal to the body that it is in ‘starvation mode’ and should try to replenish and conserve as much energy as possible. As a result, the body reduces processes that are not absolutely necessary for survival,” he said.

Until the twentieth century, people did not have ready access to foods high in fat and sugar, said Herzog. So in evolutionary terms, the body had mechanisms in place only to prevent weight loss, he said.

“Obesity is a modern epidemic, and the challenge will be to find ways of tricking the body into losing weight – and that will mean somehow circumventing or manipulating this NPY circuit, probably with drugs,” he said.

Source : Garvan Institute of Medical Research