The study, published online in the British Ecological Society’s journal Functional Ecology, found large differences in fever responses among closely related species of mice and suggests that an animal’s reproductive strategy could explain some of this intriguing variation.
Although often treated in the medical world as part of disease, fever is an essential way for many organisms to prevent or eradicate infections. But even though fever is an effective strategy for animals to protect themselves against pathogens, fever varies a great deal within and between species, and scientists are unsure why immune defences vary so much when evolution should strongly favour animals with the strongest immune systems.
Part of the reason for this variation seems to lie in the fact that fever is expensive and therefore involves trade-offs with other physiological processes. According to the lead author Professor Lynn Martin of the University of South Florida: “Fever is very costly energetically. A 1oC rise in body temperature in a warm-blooded animal requires around a 10% increase in metabolic rate.”
Martin's hypothesis is that an animal's reproductive strategy could hold important clues as to why some species favour fever more than others. In particular, he wondered whether animals that “live fast, die young” might invest fewer resources in mounting fevers to combat infections because their life history involves putting their resources into breeding quickly rather than living to a ripe old age.
He tested this hypothesis by examining fever in five species of mice of the genus Peromyscus with different reproductive strategies – some being fast living and others slow. According to Martin: “We found that fever was used by fast-living but not slow-living mice, which was surprising because we expected that fast-living mice would be unable to invest heavily in fever given their already large investments in reproductive effort. The fact that fever is robust in some species but absent in their close relatives is probably because of a combination of factors. Fever, like a lot of other immune defences, is broadly effective but not as targeted as other immune defences; this characteristic can often cause damage to host tissues, not just the parasites. Thus, fever may be a viable defence mechanism for only those organisms that can afford its high costs in terms of calories and self-destruction.”
As well as shedding new light on the interplay between animal physiology and life history, the study also may provide some perspective on human and animal health research. Rodents are the model of choice for understanding the vertebrate immune system, but this study reveals that even closely related mice use fever very differently. How might the use of fast-living rodents in biomedical research affect understanding of slow-living animals’ immune systems? Professor Martin’s next steps are to identify the molecular and hormonal pathways that mediate fever differences among species and determine the consequences of the various defence strategies for fitness.
L Martin et al (2007). Fever and sickness behaviour vary among congeneric rodents. Functional Ecology, doi: 10.1111/j.1365-2435.2007.01347.x is published online on 30 October 2007.
Scientists team up on study to save endangered African penguins
16.11.2017 | Florida Atlantic University
Climate change: Urban trees are growing faster worldwide
13.11.2017 | Technische Universität München
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
21.11.2017 | Physics and Astronomy
21.11.2017 | Physics and Astronomy
21.11.2017 | Life Sciences