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.
Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany
25.06.2018 | Fraunhofer-Institut für Betriebsfestigkeit und Systemzuverlässigkeit LBF
Dry landscapes can increase disease transmission
20.06.2018 | Forschungsverbund Berlin e.V.
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
19.07.2018 | Earth Sciences
19.07.2018 | Power and Electrical Engineering
19.07.2018 | Materials Sciences