(Press-News.org) Springtime spells tick-time. Lyme borreliosis is the most common tick-borne disease in Switzerland: around 10,000 people a year become infected with the pathogen. The actual hosts for Borrelia, however, are wild mice. Like in humans, the pathogen is also transmitted by ticks in mice. Interestingly, not all mice are equally susceptible to the bacterium and individual animals are immune to the pathogen. Scientists from the universities of Zurich and Lund headed by evolutionary biologist Barbara Tschirren reveal that the difference in vulnerability among the animals is genetic in origin.
Protective gene variant
Tschirren and colleagues examined wild mice for signs of a Borrelia infection in a large-scale field study. Borrelia afzelii – the scientific name for the bacteria – feed on mouse blood. The researchers discovered that mice with a particular variant of the antigen receptor TLR2 were around three times less susceptible to Borrelia. "The immune system of mice with this receptor variant recognizes the pathogen better and can trigger an immune response more quickly to destroy the Borrelia in time," says Tschirren. Infected mice exhibit similar symptoms to humans – especially joint complaints. Consequently, in the wild infected mice probably do not survive for very long and weakened animals soon fall victim to foxes and birds of prey.
Arms race between mice and Borrelia
The protective gene variant is advantageous for its carriers and, according to the researchers, gradually becoming prevalent in the mouse population. Nonetheless, it is unlikely that all mice will one day be resistant to Borrelia. "The increasing resistance in the host is bound to lead to adaptations in Borrelia," predicts Tschirren. "We can observe the evolutionary adaptation through the rearmament in mice and the pathogen."
People also have the antigen receptor TLR2, but not the resistant gene variant observed in mice. Whether the evolutionary arms race between mice and Borrelia will have repercussions for people remains to be seen. According to Tschirren, the bacterium does not necessarily have to become more aggressive for humans.
INFORMATION:
Literatur:
Barbara Tschirren, Martin Andersson, Kristin Scherman, Helena Westerdahl, Peer R. E. Mittl, and Lars Råberg. Polymorphisms at the innate immune receptor TLR2 are associated with Borrelia infection in a wild rodent population. Proceedings of the Royal Society B, 20130364. April 3, 2013. doi: 10.1098/rspb.2013.0364
Contact:
Prof. Barbara Tschirren
Institute of Evolutionary Biology and Environmental Studies
University of Zurich
Phone. +41 44 635 47 77
E-mail: barbara.tschirren@ieu.uzh.ch
Wild mice have natural protection against Lyme borreliosis
2013-04-04
ELSE PRESS RELEASES FROM THIS DATE:
Power behind primordial soup discovered
2013-04-04
Researchers at the University of Leeds may have solved a key puzzle about how objects from space could have kindled life on Earth.
While it is generally accepted that some important ingredients for life came from meteorites bombarding the early Earth, scientists have not been able to explain how that inanimate rock transformed into the building blocks of life.
This new study shows how a chemical, similar to one now found in all living cells and vital for generating the energy that makes something alive, could have been created when meteorites containing phosphorus minerals ...
Hallucinations of musical notation: New paper for neurology journal Brain by Oliver Sacks
2013-04-04
Professor of neurology, physician, and author Oliver Sacks M.D. has outlined case studies of hallucinations of musical notation, and commented on the neural basis of such hallucinations, in a new paper for the neurology journal Brain.
In this paper, Dr Sacks is building on work done by Dominic ffytche et al in 2000 [i], which delineates more than a dozen types of hallucinations, particularly in relation to people with Charles Bonnet syndrome (a condition that causes patients with visual loss to have complex visual hallucinations). While ffytche believes that hallucinations ...
Graduate glut spells underused skills and dissatisfaction for many
2013-04-04
Los Angeles, CA (April 04, 2013). Graduates are taking up jobs that don't fully use their skills and as a result are causing high turnover for employers, claims new research published today in the journal Human Relations, published by SAGE. The findings raise questions about today's high throughput in university education.
Policy makers in many developed and developing countries envisioned high-value economies supported in part by a highly-skilled and well-paid workforce. As a result, many nations have increased higher education (HE) access, assuming that employers will ...
Study finds dementia care costs among highest of all diseases; comparable to cancer, heart disease
2013-04-04
ANN ARBOR, Mich. — The costs of caring for people with dementia in the U.S. are comparable to – if not greater than – those for heart disease and cancer, according to new estimates by researchers at the University of Michigan Health System and nonprofit RAND Corporation.
Annual healthcare costs tied to dementia, including both formal and unpaid care, reach $159-$215 billion – rivaling the most costly major diseases – according to the findings that appear in The New England Journal of Medicine.
"Our findings show why dementia is sometimes described as a 'slow-motion ...
New camera system creates high-resolution 3-D images from up to a kilometer away
2013-04-04
A standard camera takes flat, 2-D pictures. To get 3-D information, such as the distance to a far-away object, scientists can bounce a laser beam off the object and measure how long it takes the light to travel back to a detector. The technique, called time-of-flight (ToF), is already used in machine vision, navigation systems for autonomous vehicles, and other applications, but many current ToF systems have a relatively short range and struggle to image objects that do not reflect laser light well. A team of Scotland-based physicists has recently tackled these limitations ...
Online learning: It's different
2013-04-04
The number of online education offerings has exploded in recent years, but such "virtual" classes have also been plagued by one critical question – can classes offered online cut through the maze of distractions – email, the Internet, TV and more – that face students as they sit in front of a computer?
The answer, Harvard researchers say, is to test students early and often.
By interspersing online lectures with short tests, student mind wandering decreased by 50 percent, note-taking tripled and overall retention of the material improved, said Daniel Schacter, the ...
Dartmouth researchers say a comet killed the dinosaurs
2013-04-04
In a geological moment about 66 million years ago, something killed off almost all the dinosaurs and some 70 percent of all other species living on Earth. Only those dinosaurs related to birds appear to have survived. Most scientists agree that the culprit in this extinction was extraterrestrial, and the prevailing opinion has been that the party crasher was an asteroid.
Not so, say two Dartmouth researchers. Professors Jason Moore and Mukul Sharma of the Department of Earth Sciences favor another explanation, asserting that a high-velocity comet led to the demise of ...
Asian carp DNA not widespread in the Great Lakes
2013-04-04
SOUTH BEND, IND. – Scientists from the University of Notre Dame, The Nature Conservancy, and Central Michigan University presented their findings of Asian carp DNA throughout the Great Lakes in a study published in the Canadian Journal of Fisheries and Aquatic Sciences. "The good news is that we have found no evidence that Asian carp are widespread in the Great Lakes basin, despite extensive surveys in Southern Lake Michigan and parts of lakes Erie and St Clair," said Dr. Christopher Jerde, the paper's lead author and a scientist at the University of Notre Dame, "Looking ...
Let me introduce myself -- leafcutter bee Megachile chomskyi from Texas
2013-04-04
The genus Megachile is a cosmopolitan group of solitary bees, often called leafcutter bees. This is one of the largest genera of bees, with well over 1,500 species in over 50 subgenera. A new species, Megachile chomskyi, has been found only in Texas, US. What is specific and interesting about this bee is the fact that it is among those insects which exhibit a narrow, specialized preference for pollen sources. Presumably, the irreplaceable host of M. chomskyi are the beautiful flowers of the widespread Onagraceae, or the so-called Evening-Primrose Family. The study has been ...
Amberlyst-15 can act as a catalyst for the acylation of phenols and alcohols
2013-04-04
Owing to the huge array of applications, catalysis has long been dubbed as one of the most significant areas of process and synthetic chemistry. In fact, the vast majority of all chemical industrial products – be it in the field of pharmaceutical, agricultural or polymer chemistry – involve catalysts at some stage of the manufacturing process.
Catalytic processes are generally conducted in homogeneous phase using anhydrous organic solvents (e.g. halogenated solvents, toluene, etc.) which are very toxic and hard to eliminate. The development of environmentally friendly ...