The steroid hormone testosterone regulates the expression of reproductive behaviors and sexual traits of many animal species. While high levels of testosterone are required for reproductive activities or for the expression of sexual traits, these are often costly, and can lead, for instance, to increased parasite infection. Such costs would also ensure honesty in sexual signals or behavior used by animals for assessing the healthiness of a potential mate.
The mechanisms linking elevated testosterone and increased parasite infection remains little know in wild animals. One possibility is that testosterone modifies behavior and increases exposure to infective parasite larvae. An alternative mechanism is related to the physiological actions of testosterone, which cause increased susceptibility to parasites.
In an article in the August 2005 issue of The American Naturalist, François Mougeot and colleagues test to determine which mechanism was most likely in a wild game bird of the UK, the red grouse. Using a new treatment, which increased testosterone concentration while blocking its direct actions (by blocking testosterone receptors), they show that the mechanism linking testosterone to parasite infection is via increased susceptibility, and that the action of testosterone on host parasite defense was most likely indirect, via cascading effects mediated by other hormones.
Carrie Olivia Adams | EurekAlert!
Obstructing the ‘inner eye’
07.07.2017 | Friedrich-Schiller-Universität Jena
Drone vs. truck deliveries: Which create less carbon pollution?
31.05.2017 | University of Washington
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision
Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...
19.07.2017 | Event News
12.07.2017 | Event News
12.07.2017 | Event News
20.07.2017 | Information Technology
20.07.2017 | Materials Sciences
20.07.2017 | Physics and Astronomy