Biologists on Guam are trying to find out if mildly toxic dead mice can help eradicate an invasive species of snake that has caused millions of dollars in damages by creating power outages on the island.

Crews on Monday distributed mice packed with 80 milligrams of acetaminophen on two plots in a test to kill brown tree snakes, which were accidentally introduced to the island about 60 years ago.

Representatives from several federal agencies watched the aerial bait drop, Pacific Daily News reported.

The mice should not affect other species, said U.S. Department of Agriculture wildlife services biologist Dan Vice, who has worked on snake eradication for more than a decade.

"The risk to nontargets is slight," Vice said. "It would take 500 baits to kill a pig (or dog and) 15 baits to kill a cat."

A pilot project with 280 mice in 2010 led to more aerial bait drops that began in September. Research and the drops have cost $8 million annually with funding from the Interior and Defense departments.

An estimated 1 to 2 million snakes live on the island. Aerial bait drops might be the most efficient way to control the population without affecting deer or pigs, Vice said.

"If it proves to be successful, then we may potentially start ramping up the efforts and doing this on a larger basis across more of Guam," Vice said.

Mice were dropped Monday on two 136-acre plots, a combined area about the size of 210 football fields. Some mice were implanted with tiny radios to allow the USDA to determine whether mice were eaten.

Biologists are also tracking populations of small animals, which will increase with fewer snakes.

The mice drops are only for area where humans don't live, Vice said.

No deaths from the venomous bite of a brown tree snake have been recorded, Vice said. Most bites cause no more damage to an adult than a bee sting, he said. But Brown tree snakes cause problems by creating outages on the Guam Power Authority power grid with damage reaching $1 million to $4 million annually, according USDA documents.

Major substations use special fences to keep snakes out. Traps on fences catch about 8,000 snakes per year, Vice said.

A stable population of brown tree snakes could be disastrous to Hawaii, Vice said, and the threat of them spreading is real. Guam ports use snake-sniffing dogs to detect invasive species.

Reactivating expression of the RNA-binding protein Lin28a in mice leads to improved regrowth of hair follicles, as well as of cartilage, bone, and mesenchyme after ear and digit injuries, according to a study published in Cell Magazine last week (November 7). Harvard Medical School’s George Daley and his colleagues have shown in several models of tissue injury that “Lin28a enhances tissue repair in some adult tissues by reprogramming cellular bioenergetics,” as they wrote in their paper.

“It sounds like science fiction, but Lin28a could be part of a healing cocktail that gives adults the superior tissue repair seen in juveniles,” Daley said in a statement.

However, not every tissue injury model showed improved healing with increased expression of Lin28a. “The fact that it doesn't work sometimes is even more interesting because it raises the question why,” the University of Michigan’s Daniel Goldman, who was not a part of the study, told Nature.

Study coauthor Shyh-Chang Ng added that the perceived renewing effects of Lin28a are particularly interesting because of the RNA-binding protein’s prevalence. “Most biologists would think that you need a special factor to generate the healing pathway, but this is a thing that every cell has,” Ng told Nature.

Chronic infection with the parasite Toxoplasma gondii can make mice lose their innate, hard-wired fear of cats. This loss of their innate fear may persist after the parasite is no longer detectable in their brains, suggesting that initial infection may cause permanent changes in the mechanisms underlying their fear of predators. The results are published September 18 in the open access journal PLOS ONE by Wendy Ingram and colleagues from the University of California, Berkeley.
The Toxoplasma parasite can be deadly, causing spontaneous abortion in pregnant women or killing immune-compromised patients, but it has even stranger effects in mice.
Infected mice lose their fear of cats, which is good for both cats and the parasite, because the cat gets an easy meal and the parasite gets into the cat's intestinal track, the only place it can sexually reproduce and continue its cycle of infection.
New research by graduate student Wendy Ingram at the University of California, Berkeley, reveals a scary twist to this scenario: the parasite's effect seem to be permanent. The fearless behavior in mice persists long after the mouse recovers from the flu-like symptoms of toxoplasmosis, and for months after the parasitic infection is cleared from the body, according to research published today (Sept. 18) in the journal PLOS ONE.
"Even when the parasite is cleared and it's no longer in the brains of the animals, some kind of permanent long-term behavior change has occurred, even though we don't know what the actual mechanism is," Ingram said. She speculated that the parasite could damage the smell center of the brain so that the odor of cat urine can't be detected. The parasite could also directly alter neurons involved in memory and learning, or it could trigger a damaging host response, as in many human autoimmune diseases.
Ingram became interested in the protozoan parasite, Toxoplasma gondii, after reading about its behavior-altering effects in mice and rats and possible implications for its common host, the domesticated cat, and even humans. One-third of people around the world have been infected with Toxoplasma and probably have dormant cysts in their brains. Kept in check by the body's immune system, these cysts sometimes revive in immune-compromised people, leading to death, and some preliminary studies suggest that chronic infection may be linked to schizophrenia or suicidal behavior.

Pregnant women are already warned to steer clear of kitty litter, since the parasite is passed through cat feces and can cause blindness or death in the fetus. One main source of spread is undercooked pork, Ingram said.
With the help of Michael Eisen and Ellen Robey, UC Berkeley professors of molecular and cell biology, Ingram set out three years ago to discover how Toxoplasma affects mice's hard-wired fear of cats. She tested mice by seeing whether they avoided bobcat urine, which is normal behavior, versus rabbit urine, to which mice don't react. While earlier studies showed that mice lose their fear of bobcat urine for a few weeks after infection, Ingram showed that the three most common strains of Toxoplasma gondii make mice less fearful of cats for at least four months.
Using a genetically altered strain of Toxoplasma that is not able to form cysts and thus is unable to cause chronic infections in the brain, she demonstrated that the effect persisted for four months even after the mice completely cleared the microbe from their bodies. She is now looking at how the mouse immune system attacks the parasite to see whether the host's response to the infection is the culprit.
"This would seem to refute – or at least make less likely – models in which the behavior effects are the result of direct physical action of parasites on specific parts of the brain," Eisen wrote in a blog post about the research.
"The idea that this parasite knows more about our brains than we do, and has the ability to exert desired change in complicated rodent behavior, is absolutely fascinating," Ingram said. "Toxoplasma has done a phenomenal job of figuring out mammalian brains in order to enhance its transmission through a complicated life cycle."

Scientists in Japan cloned a mouse from a drop of blood. Moving blood cells taken from the tail of the mouse donor were used to create the clone, said researchers from the center Ricken Bioresources. Some time ago the same scientists have created nearly 600 exact genetic copies of a mouse.

Mice were cloned from different sources of donor cells, including white blood cells of the lymph nodes, bone marrow and liver. Japanese researchers studied whether the moving blood cells can be used for cloning. Their goal was to find an easy source of donor cells for cloning valuable scientifically types of laboratory mice.

Scientists led by Atsuo Ogura of Bioresources Rikes center in Tsukuba, blood taken from the tail of a mouse donor, isolated white blood cells and used kernel cloning experiments using the same technique as for the cloning of Dolly the sheep in Edinburgh.

The process, known as somatic cell nuclear transfer involving transfer of the nucleus from a cell in the adult body as blood cells or skin unfertilized egg, which was removed the nucleus. Scientists, whose research was published in the journal Biology of Reproduction, said that it shows for the first time that mice can be cloned using the nucleus of peripheral blood cells.

"These cells can be used to clone immediately after isolation, without requiring euthanasia of donor" complemented researchers.

Researchers in Japan have produced 26 successful generations of cloned mice from a single individual. That's a total of 598 mice, all of whom are essentially genetic duplicates. The achievement was made possible by a new cloning technique that allowed researchers to overcome genetic degradation problems characteristic of generational re-cloning. The breakthrough shows that mammalian cloning lines can be extended and reproduced without limit.

Indeed, animal re-cloning (i.e. cloning a clone) works great, but up to a point. Eventually, over the course of several generations, a clonal line will ultimately fail, the result of accumulated lethal genetic and epigenetic abnormalities. But the Japanese researchers devised a crafty biohack that appears to remedy this problem.

The new technique, developed by Teruhiko Wakayama of the RIKEN Center for Developmental Biology in Kobe, Japan, was so successful that it resulted in well over two dozen generations of re-cloned mice. Moreover, the cloning efficiency did not decrease over the course of those generations, and the project was allowed to continue indefinitely (and in fact, the project is still going!). In all, nearly 600 viable offspring were produced from a single donor mouse. The experiment started seven years ago and it is considered the largest cloning project using a mammal to date.

Wakayama and his team achieved this by using the standard cloning technique, somatic cell nuclear transfer (SCNT), and adding a histone deacetylase inhibitor (trichostatin), and other chemicals to the process.

In SCNT, the nucleus of a somatic cell is transferred to the cytoplasm of an egg that has had its nucleus removed (an enucleated egg). Once inside the egg, the somatic nucleus is reprogrammed to become a zygote nucleus, what is really a fertilized egg.

But as noted, this can’t be done indefinitely, as genetic problems start to creep in over successive generations. But adding the HDI to the mix seemed to do the trick. It's a class of compounds that interfere with the function of histone deacetylase, a class of enzymes that allow histones (proteins that package and order the DNA into nucleosomes) to wrap DNA more tightly. They can also be used to alter gene expression.

According to the researchers, the cloned mice had normal biological features, including regular lifespans and reproductive capabilities. That said, genetic analysis did show some minor abnormalities, including an oversized placenta. But none of these characteristics had a detrimental impact on the line’s clonal health. The researchers noted that “serially recloned mice have the same characteristics as standard clones.”

Their results show that repeated iterative re-cloning is possible. The researchers wrote that “with adequately efficient techniques, it may be possible to re-clone animals indefinitely.”

Once refined, the technique could result in the large-scale production of cloned animals for farming or conservation purposes. Moreover, animals can continue to be cloned long after the source individual has died.